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                             MED SHIP MAN

                          By MURRAY LEINSTER

                          Illustrated by ENSH

           [Transcriber's Note: This etext was produced from
                     Galaxy Magazine October 1963.
         Extensive research did not uncover any evidence that
         the U.S. copyright on this publication was renewed.]




                  His work was healing the sick--but
                     this planet was already dead!


I

Calhoun regarded the communicator with something like exasperation as
his taped voice repeated a standard approach-call for the twentieth
time. But no answer came, which had become irritating a long time ago.
This was a new Med Service sector for Calhoun. He'd been assigned to
another man's tour of duty because the other man had been taken down
with romance. He'd gotten married, which ruled him out for Med Ship
duty. So now Calhoun listened to his own voice endlessly repeating a
call that should have been answered immediately.

Murgatroyd the _tormal_ watched with beady, interested eyes. The planet
Maya lay off to port of the Med Ship _Esclipus Twenty_. Its almost
circular disk showed full size on a vision screen beside the ship's
control board. The image was absolutely clear and vividly colored.
There was an ice cap in view. There were continents. There were seas.
The cloud system of a considerable cyclonic disturbance could be noted
off at one side, and the continents looked reasonably as they should,
and the seas were of that muddy, indescribable tint which indicates
deep water.

Calhoun's own voice, taped an hour earlier, sounded in a speaker as it
went again to the communicator and then to the extremely visible world
a hundred thousand miles away.

"_Calling ground_," said Calhoun's recorded voice. "_Med Ship_ Esclipus
Twenty _calling ground to report arrival and ask coordinates for
landing. Our mass is fifty standard tons. Repeat, five-oh tons. Purpose
of landing, planetary health inspection._"

       *       *       *       *       *

The recorded voice stopped. There was silence except for the taped
random noises which kept the inside of the ship from feeling like the
inside of a tomb.

Murgatroyd said: "_Chee?_"

Calhoun said ironically, "Undoubtedly, Murgatroyd. Undoubtedly!
Whoever's on duty at the spaceport stepped out for a moment, or dropped
dead, or did something equally inconvenient. We have to wait until he
gets back or somebody else takes over."

Murgatroyd said "_Chee!_" again and began to lick his whiskers. He
knew that when Calhoun called on the communicator, another human voice
should reply. Then there should be conversation, and shortly the
force-fields of a landing-grid should take hold of the Med Ship and
draw it planet-ward. In time it ought to touch ground in a spaceport
with a gigantic, silvery landing-grid rising skyward all about it.
Then there should be people greeting Calhoun cordially and welcoming
Murgatroyd with smiles and petting.

"_Calling ground_," said the recorded voice yet again. "_Med Ship_
Esclipus Twenty--"

It went on through the formal notice of arrival. Murgatroyd waited
in pleasurable anticipation. When the Med Ship arrived at a port of
call humans gave him sweets and cakes, and they thought it charming
that he drank coffee just like a human, only with more gusto. Aground,
Murgatroyd moved zestfully in society while Calhoun worked. Calhoun's
work was conferences with planetary health officials, politely
receiving such information as they thought important, and tactfully
telling them about the most recent developments in medical science as
known to the Interstellar Medical Service.

"Somebody," said Calhoun darkly, "is going to catch the devil for this!"

The communicator loudspeaker spoke abruptly.

"Calling Med Ship," said a voice. "Calling Med Ship _Esclipus Twenty_!
Liner _Candida_ calling. Have you had an answer from ground?"

Calhoun blinked. Then he said curtly:

"Not yet. I've been calling all of half an hour, and never a word out
of them!"

"We've been in orbit twelve hours," said the voice from emptiness.
"Calling all the while. No answer. We don't like it."

Calhoun flipped a switch that threw a vision screen into circuit
with the ship's electron telescope. A starfield appeared and shifted
wildly. Then a bright dot centered itself. He raised the magnification.
The bright dot swelled and became a chubby commercial ship, with
the false ports that passengers like to believe they looked through
when in space. Two relatively large cargo ports on each side showed
that it carried heavy freight in addition to passengers. It was one
of those workhorse intra-cluster ships that distributed the freight
and passengers the long-haul liners dumped off only at established
transshipping ports.

Murgatroyd padded across the Med Ship's cabin and examined the image
with a fine air of wisdom. It did not mean anything to him, but
_tormals_ imitate human actions as parrots and parrakeets imitate human
speech. He said, "_Chee!_" as if making an observation of profound
significance, then went back to the cushion and again curled up.

"We don't see anything wrong aground," the liner's voice complained,
"but they don't answer calls! We don't get any scatter-signals either.
We went down to two diameters and couldn't pick up a thing. And we have
a passenger to land. He insists on it!"

       *       *       *       *       *

By ordinary, communications between different places on a planet's
surface use frequencies the ion-layers of the atmosphere either reflect
or refract down past the horizon. But there is usually some small
leakage to space, and line-of-sight frequencies are generally abundant.
It is one of the annoyances of a ship coming in to port that space near
most planets is usually full of local signals.

"I'll check," said Calhoun curtly. "Stand by."

The _Candida_ would have arrived off Maya as the Med Ship had done, and
called down as Calhoun had been doing. It was very probably a ship on
schedule and the grid operator at the spaceport should have expected
it. Space commerce was important to any planet, comparing more or less
with the export-import business of an industrial nation in ancient
times on Earth. Planets had elaborate traffic-aid systems for the
cargo-carriers which moved between solar systems as they'd once moved
between continents on Earth. Such traffic aids were very carefully
maintained. Certainly for a spaceport landing-grid not to respond to
calls for twelve hours running seemed ominous.

"We've been wondering," said the _Candida_ querulously, "if there could
be something radically wrong below. Sickness, for example."

The word "sickness" was a substitute for a more alarming word. But a
plague had nearly wiped out the population of Dorset, once upon a time,
and the first ships to arrive after it had broken out most incautiously
went down to ground, and so carried the plague to their next two ports
of call. Nowadays quarantine regulations were enforced very strictly
indeed.

"I'll try to find out what's the matter," said Calhoun.

"We've got a passenger," repeated the _Candida_ aggrievedly, "who
insists that we land him by space-boat if we don't make a ship landing.
He says he has important business aground."

Calhoun did not answer. The rights of passengers were extravagantly
protected, these days. To fail to deliver a passenger to his
destination entitled him to punitive damages which no spaceline could
afford. So the Med Ship would seem heaven-sent to the _Candida's_
skipper. Calhoun could relieve him of responsibility.

The telescope screen winked and showed the surface of the planet a
hundred thousand miles away. Calhoun glared at the image on the port
screen and guided the telescope to the spaceport city--Maya City. He
saw highways and blocks of buildings. He saw the spaceport and its
landing-grid. He could see no motion, of course.

He raised the magnification. He raised it again. Still no motion. He
upped the magnification until the lattice-pattern of the telescope's
amplifying crystal began to show. But at the ship's distance from the
planet, a ground-car would represent only the fortieth of a second of
arc. There was atmosphere, too, with thermals; anything the size of a
ground-car simply couldn't be seen.

But the city showed quite clearly. Nothing massive had happened to it.
No large-scale physical disaster had occurred. It simply did not answer
calls from space.

       *       *       *       *       *

Calhoun flipped off the screen.

"I think," he said irritably into the communicator microphone, "I
suspect I'll have to make an emergency landing. It could be something
as trivial as a power failure--" but he knew that was wildly
improbable--"or it could be--anything. I'll land on rockets and tell
you what I find."

The voice from the _Candida_ said hopefully:

"Can you authorize us to refuse to land our passenger for his own
protection? He's raising the devil! He insists that his business
demands that he be landed."

A word from Calhoun as a Med Service man would protect the spaceliner
from a claim for damages. But Calhoun didn't like the look of things.
He realized, distastefully, that he might find practically anything
down below. He might find that he had to quarantine the planet and
himself with it. In such a case he'd need the _Candida_ to carry word
of the quarantine to other planets and thus to Med Service sector
headquarters.

"We've lost a lot of time," insisted the _Candida_. "Can you authorize
us--"

"Not yet," said Calhoun. "I'll tell you when I land."

"But--"

"I'm signing off for the moment," said Calhoun. "Stand by."

He headed the little ship downward, and as it gathered velocity he went
over the briefing sheets covering this particular world. He'd never
touched ground here before. His occupation, of course, was seeing to
the dissemination of medical science as it developed under the Med
Service. The Service itself was neither political nor administrative.
But it was important. Every human-occupied world was supposed to have
a Med Ship visit at least once in four years to verify the state of
public health.

Med Ship men like Calhoun offered advice on public-health problems.
When something out of the ordinary turned up, the Med Service had a
staff of researchers who hadn't been wholly baffled yet. There were
great ships which could carry the ultimate in laboratory equipment and
specialized personnel to any place where they were needed. Not less
than a dozen inhabited worlds in this sector alone owed the survival
of their populations to the Med Service, and the number of those which
couldn't have been colonized without Med Service help was legion.

Calhoun reread the briefing. Maya was one of four planets in this
general area whose life systems seemed to have had a common origin,
suggesting that the Arrhenius theory of space-traveling spores was true
in some limited sense. A genus of ground-cover plants with motile stems
and leaves and cannibalistic tendencies was considered strong evidence
of common origin.

The planet had been colonized for two centuries now, and produced
organic compounds of great value from indigenous plants, most of
which were used in textile manufacture. There were no local endemic
infections to which men were susceptible. A number of human-use crops
were grown. Cereals, grasses and grains, however, could not be grown
because of the native ground-cover motile-stem plants. All wheat and
cereal food had to be imported, which fact severely limited Maya's
population. There were about two million people on the planet, settled
on a peninsula in the Yucatan Sea and a small area of mainland.
Public-health surveys had shown a great many things about a great
many subjects ... but there was no mention of anything to account for
the failure of the spaceport to respond to arrival calls from space.
Naturally!

The Med Ship drove on down, and the planet revolved beneath it.

As Maya's sunlit hemisphere enlarged, Calhoun kept the telescope's
field wide. He saw cities, and vast areas of cleared land where native
plants were grown as raw materials for the organics' manufacturies. He
saw very little true chlorophyll green, though. Mayan foliage tended to
a dark olive color.

       *       *       *       *       *

At fifty miles he was sure that the city streets were empty even
of ground-car traffic. There was no spaceship aground in the
landing-grid. There were no ground-cars in motion on the splendid,
multiple-lane highways.

At thirty miles altitude there were still no signals in the atmosphere,
though when he tried amplitude-modulation reception he picked up
static. But there was no normally modulated signal on the air at any
frequency. At twenty miles--no. At fifteen miles, broadcast power was
available, which proved that the landing-grid was working as usual,
tapping the upper atmosphere for electric charges to furnish power for
all the planet's needs.

From ten miles down to ground-touch, Calhoun was busy.

It is not too difficult to land a ship on rockets, with reasonably
level ground to land on. But landing at a specific spot is something
else. Calhoun juggled the ship to descend inside the grid itself. His
rockets burned out pencil-thin holes through the clay and stone beneath
the tarmac. He cut them off.

Silence. Stillness. The Med Ship's outside microphones picked up small
noises of wind blowing over the city. There was no other sound at all.

--No. There was a singularly deliberate clicking sound, not loud and
not fast. Perhaps a click--a double click--every two seconds. That was
all.

Calhoun went into the airlock, with Murgatroyd frisking a little in
the expectation of great social success among the people of this world.
When Calhoun cracked the outer airlock door he smelled something. It
was a faintly sour, astringent odor that had the quality of decay in
it. But it was no kind of decay he recognized. Again stillness and
silence. No traffic-noise; not even the almost inaudible murmur that
every city has in all its ways at all hours. The buildings looked as
buildings should look at daybreak, except that the doors and windows
were open. It was somehow shocking.

A ruined city is dramatic. An abandoned city is pathetic. This was
neither. It was something new. It felt as if everybody had walked away,
out of sight, within the past few minutes.

Calhoun headed for the spaceport building with Murgatroyd ambling
puzzledly at his side. Murgatroyd was disturbed. There should be people
here! They should welcome Calhoun and admire him--Murgatroyd--and he
should be a social lion with all the sweets he could eat and all the
coffee he could put into his expandable belly. But nothing happened!
Nothing at all.

"_Chee?_" he asked anxiously.

"They've gone away," growled Calhoun. "They probably left in
ground-cars. There's not one in sight."

There wasn't. Calhoun could look out through the grid foundations
and see long, sunlit and absolutely empty streets. He arrived at the
spaceport building. There was--there had been--a green area about the
base of the structure. There was not a living plant left. Leaves were
wilted and limp. The remains had become almost a jelly of collapsed
stems and blossoms of dark olive-green. The plants were dead; but not
long enough to have dried up. They might have wilted two or three days
before.

Calhoun went in the building. The spaceport log lay open on a desk. It
recorded the arrival of freight to be shipped away--undoubtedly--on the
_Candida_ now uneasily in orbit somewhere aloft. There was no sign of
disorder. It was exactly as if the people here had walked out to look
at something interesting, and hadn't come back.

Calhoun trudged out of the spaceport and to the streets and buildings
of the city proper. It was incredible! Doors were opened or unlocked.
Merchandise in the shops lay on display, exactly as it had been spread
out to interest customers. There was no sign of confusion anywhere.
Even in a restaurant there were dishes and flatware on the tables. The
food in the plates was stale, as if three days old, but it hadn't yet
begun to spoil. The appearance of everything was as if people at their
meals had simply, at some signal, gotten up and walked out without any
panic or disturbance.

Calhoun made a wry face. He'd remembered something. Among the tales
that had been carried from Earth to the other worlds of the galaxy
there was a completely unimportant mystery story which people still
sometimes tried to write an ending to. It was the story of an ancient
sailing ship called the _Marie Celeste_, which was found drifting
aimlessly in the middle of the ocean. There was food on the cabin
table, and the galley stove was still warm. There was no sign of any
trouble, or terror, or disturbance which might cause the ship to be
abandoned. But there was not a living soul on board. Nobody had ever
been able to contrive a believable explanation.

"Only," said Calhoun to Murgatroyd, "this is on a larger scale. The
people of this city walked out about three days ago, and didn't come
back. Maybe all the people on the planet did the same, since there's
not a communicator in operation anywhere. To make the understatement
of the century, Murgatroyd, I don't like this. I don't like it a bit!"


II

On the way back to the Med Ship, Calhoun stopped at another place
where, on a grass-growing planet, there would have been green sward.
There were Earth-type trees, and some native ones, and between them
there should have been a lawn. The trees were thriving, but the
ground-cover plants were collapsed and rotting.

Calhoun picked up a bit of the semi-slime and smelled it. It was
faintly sour, astringent, the same smell he'd noticed when he opened
the airlock door. He threw the stuff away and brushed off his hands.
Something had killed the ground-cover plants which had the habit of
killing Earth-type grass when planted here.

He listened. Everywhere that humans live, there are insects and birds
and other tiny creatures which are essential parts of the ecological
system to which the human race is adjusted. They have to be carried to
and established upon every new world that mankind hopes to occupy. But
there was no sound of such living creatures here.

It was probable that the bellowing roar of the Med Ship's emergency
rockets was the only real noise the city had heard since its people
went away.

The stillness bothered Murgatroyd. He said, "_Chee!_" in a subdued
tone and stayed close to Calhoun. Calhoun shook his head. Then he said
abruptly:

"Come along, Murgatroyd!"

He went back to the building housing the grid controls. He didn't look
at the spaceport log this time. He went to the instruments recording
the second function of a landing-grid. In addition to lifting up and
letting down ships of space, a landing-grid drew down power from the
ions of the upper atmosphere and broadcast it. It provided all the
energy that humans on a world could need. It was solar power, in a way,
absorbed and stored by a layer of ions miles high, which then could be
drawn on and distributed by the grid. During his descent Calhoun had
noted that broadcast power was still available. Now he looked at what
the instruments said.

The needle on the dial showing power-drain moved slowly back and forth.
It was a rhythmic movement, going from maximum to minimum power-use,
and then back again. Approximately six million kilowatts was being
taken out of the broadcast every two seconds for half of one second.
Then the drain cut off for a second and a half, and went on again for
half a second.

Frowning, Calhoun raised his eyes to a very fine color photograph on
the wall above the power dials. It was a picture of the human-occupied
part of Maya, taken four thousand miles out in space. It had been
enlarged to four feet by six, and Maya City could be seen as an
irregular group of squares and triangles measuring a little more than
half an inch by three-quarters. The detail was perfect. It was possible
to see perfectly straight, infinitely thin lines moving out from the
city. They were multiple-lane highways, mathematically straight from
one city to another, and then mathematically straight--though at a new
angle--until the next. Calhoun stared thoughtfully at them.

"The people left the city in a hurry," he told Murgatroyd, "and there
was little confusion, if any. So they knew in advance that they might
have to go. They were ready for it. If they took anything, they had it
ready packed in their cars. But they hadn't been sure they'd have to go
because they were going about their businesses as usual. All the shops
were open and people were eating in restaurants, and so on."

Murgatroyd said, "_Chee!_" as if in full agreement.

"Now," demanded Calhoun, "where did they go? The question's really
where could they go! There were about eight hundred thousand people in
this city. There'd be cars for everyone, of course, and two hundred
thousand cars would take everybody. But that's a lot of ground-cars!
Put 'em two hundred feet apart on a highway, and that's twenty-six
cars to the mile on each lane. Run them at a hundred miles an hour on
a twelve-lane road--using all lanes one way--and that's twenty-six
hundred cars per lane per hour, and that's thirty-one thousand ... two
highways make sixty-two ... three highways.... With two highways they
could empty the city in under three hours, and with three highways
close to two. Since there's no sign of panic, that's what they must
have done. Must have worked it out in advance, too. Maybe they'd done
it before it happened ... whatever it was that happened."

       *       *       *       *       *

He searched the photograph which was so much more detailed than a map.
There were mountains to the north of Maya City, but only one highway
led north. There were more mountains to the west. One highway went into
them, but not through. To the south there was sea, which curved around
some three hundred miles from Maya City and put the human colony on
Maya on a peninsula.

"They went east," said Calhoun presently. He traced lines with his
finger. "Three highways go east; that's the only way they could go
quickly. They hadn't been sure they'd have to go but they knew where to
go when they did. So when they got their warning, they left. On three
highways, to the east. And we'll follow them and ask what the hell they
ran away from. Nothing's visible here!"

He went back to the Med Ship, Murgatroyd skipping with him.

As the airlock door closed behind them, he heard a click from the
outside-microphone speakers. He listened. It was a doubled clicking,
as of something turned on and almost at once turned off again. There
was a two-second cycle, the same as that of the power drain. Something
drawing six million kilowatts went on and immediately off again every
two seconds. It made a sound in speakers linked to outside microphones,
but it didn't make a noise in the air. The microphone clicks were
induction; pick-up; like cross-talk on defective telephone cables.

Calhoun shrugged his shoulders almost up to his ears. He went to the
communicator.

"Calling _Candida_--" he began, and the answer almost leaped down his
throat.

"_Candida_ to Med Ship. Come in! Come in! What's happened down there?"

"The city's deserted without any sign of panic," said Calhoun, "and
there's power and nothing seems to be broken down. But it's as if
somebody had said, 'Everybody clear out' and they did. That doesn't
happen on a whim! What's your next port of call?"

The _Candida's_ voice told him, hopefully.

"Take a report," commanded Calhoun. "Deliver it to the public health
office immediately you land. They'll get it to Med Service sector
headquarters. I'm going to stay here and find out what's been going on."

He dictated, growing irritated as he did so because he couldn't explain
what he reported. Something serious had taken place, but there was no
clue as to what it was. Strictly speaking, it wasn't certainly a public
health affair. But any emergency the size of this one involved public
health factors.

"I'm remaining aground to investigate," finished Calhoun. "I will
report further when or if it is possible. Message ends."

"What about our passenger?"

"To the devil with your passenger!" said Calhoun peevishly. "Do as you
please!"

       *       *       *       *       *

He cut off the communicator and prepared for activity outside the ship.
Presently he and Murgatroyd went to look for transportation. The Med
Ship couldn't be used for a search operation; it didn't carry enough
rocket fuel. They'd have to use a ground vehicle.

It was again shocking to note that nothing had moved but sun shadows.
Again it seemed that everybody had simply walked out of some door or
other and failed to come back. Calhoun saw the windows of jewelers'
shops. Treasures lay unguarded in plain view. He saw a florist's shop.
Here there were Earth-type flowers apparently thriving, and some
strange beautiful flowers with olive-green foliage which throve as well
as the Earth-plants. There was a cage in which a plant had grown, and
that plant was wilting and about to rot. But a plant that had to be
grown in a cage....

He found a ground-car agency, perhaps for imported cars, perhaps for
those built on Maya. He went in and from the cars on display he chose
one, an elaborate sports car. He turned its key and it hummed. He drove
it carefully out into the empty street, Murgatroyd sitting interestedly
beside him.

"This is luxury, Murgatroyd," said Calhoun. "Also it's grand theft. We
medical characters can't usually afford such things. Or have an excuse
to steal them. But these are parlous times, so we take a chance."

"_Chee!_" said Murgatroyd.

"We want to find a fugitive population and ask what they ran away from.
As of the moment, it seems that they ran away from nothing. They may be
pleased to know they can come back."

Murgatroyd again said, "_Chee!_"

Calhoun drove through vacant ways. It was somehow nerve-racking. He
felt as if someone should pop out and say "Boo!" at any instant. He
discovered an elevated highway and a ramp leading up to it. At a
cloverleaf he drove eastward, watching sharply for any sign of life.
There was none.

He was nearly out of the city when he felt the chest impact of a sonic
boom, and then heard a trailing away growling sound which seemed to
come from farther away as it died out. It was the result of something
traveling faster than sound, so that the noise it made far away had to
catch up with the sound it emitted nearby.

He stared up. He saw a parachute blossom as a bare speck against the
blue. Then he heard the even deeper-toned roaring of a supersonic craft
climbing skyward. It could be a spaceliner's lifeboat, descended into
atmosphere and going out again.

It was. It had left a parachute behind, and now went back to space to
rendezvous with its parent ship.

"That," said Calhoun impatiently, "will be the _Candida's_ passenger.
He was insistent enough."

He scowled. The _Candida's_ voice had said its passenger demanded to
be landed for business reasons. And Calhoun had a prejudice against
some kinds of business men who would think their own affairs more
important than anything else. Two standard years before, he'd made a
planetary health inspection on Texia II, in another galactic sector. It
was a llano planet and a single giant business enterprise. Illimitable
prairies had been sown with an Earth-type grass which destroyed
the native ground-cover--the reverse of the ground-cover situation
here--and the entire planet was a monstrous range for beef cattle.
Dotted about were gigantic slaughterhouses, and cattle in masses of
tens of thousands were shifted here and there by ground-induction
fields which acted as fences. Ultimately the cattle were driven by
these same induction fences to the slaughter houses and actually into
the chutes where their throats were slit. Every imaginable fraction of
a credit of profit was extracted from their carcasses, and Calhoun had
found it appalling.

He was not sentimental about cattle, but the complete cold-bloodedness
of the entire operation sickened him. The same cold-bloodedness was
practised toward the human employees who ran the place. Their living
quarters were sub-marginal. The air stank of cattle murder. Men worked
for the Texia Company or they did not work. If they did not work
they did not eat. If they worked and ate,--Calhoun could see nothing
satisfying in being alive on a world like that! His report to Med
Service had been biting. He'd been prejudiced against businessmen ever
since.

       *       *       *       *       *

But a parachute descended, blowing away from the city. It would land
not too far from the highway he followed. And it didn't occur to
Calhoun not to help the unknown chutist. He saw a small figure dangling
below the chute. He slowed the ground-car as he estimated where the
parachute would land.

He was off the twelve-lane highway and on a feeder road when the chute
was a hundred feet high. He was racing across a field of olive-green
plants that went all the way to the horizon when the parachute actually
touched ground. There was a considerable wind. The man in the harness
bounced. He didn't know how to spill the air. The chute dragged him.

Calhoun sped ahead, swerved and ran into the chute. He stopped the car
and the chute stopped with it. He got out.

The man lay in a hopeless tangle of cordage. He thrust unskilfully at
it. When Calhoun came up he said suspiciously:

"Have you a knife?"

Calhoun offered a knife, politely opening its blade. The man slashed
at the cords and freed himself. There was an attache case lashed to
his chute harness. He cut at those cords. The attache case not only
came clear, but opened. It dumped out an incredible mass of brand new,
tightly packed interstellar credit certificates. Calhoun could see that
the denominations were one thousand and ten thousand credits. The man
from the chute reached under his armpit and drew out a blaster.

It was not a service weapon. It was elaborate, practically a toy. With
a dour glance at Calhoun he put it in a side pocket and gathered up
the scattered money. It was an enormous sum, but he packed it back. He
stood up.

"My name is Allison," he said in an authoritative voice. "Arthur
Allison. I'm much obliged. Now I'll ask you to take me to Maya City."

"No," said Calhoun politely. "I just left there. It's deserted. I'm not
going back. There's nobody there."

"But I've important bus--" The other man stared. "It's deserted? But
that's impossible!"

"Quite," agreed Calhoun, "but it's true. It's abandoned. Uninhabited.
Everybody's left it. There's no one there at all."

The man who called himself Allison blinked unbelievingly. He swore.
Then he raged profanely.

But he was not bewildered by the news. Which, upon consideration, was
itself almost bewildering. But then his eyes grew shrewd. He looked
about him.

"My name is Allison," he repeated, as if there were some sort of magic
in the word. "Arthur Allison. No matter what's happened, I've some
business to do here. Where have the people gone? I need to find them."

"I need to find them too," said Calhoun. "I'll take you with me, if you
like."

"You've heard of me." It was a statement, confidently made.

"Never," said Calhoun politely. "If you're not hurt, suppose you get in
the car? I'm as anxious as you are to find out what's happened. I'm Med
Service."

       *       *       *       *       *

Allison moved toward the car.

"Med Service, eh? I don't think much of the Med Service! You people
try to meddle in things that are none of your business!"

Calhoun did not answer. The muddy man, clutching the attache case
tightly, waded through the olive-green plants to the car and climbed
in. Murgatroyd said cordially, "_Chee-chee!_" but Allison viewed him
with distaste.

"What's this?"

"He's Murgatroyd," said Calhoun. "He's a _tormal_. He's Med service
personnel."

"I don't like beasts," said Allison coldly.

"He's much more important to me than you are," said Calhoun, "if the
matter should come to a test."

Allison stared at him as if expecting him to cringe. Calhoun did not.
Allison showed every sign of being an important man who expected his
importance to be recognized and catered to. When Calhoun stirred
impatiently he got into the car and growled a little. Calhoun took
his place. The ground-car hummed. It rose on the six columns of air
which took the place of wheels and slid across the field of dark-green
plants, leaving the parachute deflated across a number of rows, and a
trail of crushed-down plants where it had moved.

It reached the highway again. Calhoun ran the car up on the highway's
shoulder, and then suddenly checked. He'd noticed something.

He stopped the car and got out. Where the ploughed field ended, and
before the coated surface of the highway began, there was a space where
on another world one would expect to see green grass.

On this planet grass did not grow; but there would normally be some
sort of self-planted vegetation where there was soil and sunshine and
moisture. There had been such vegetation here, but now there was only a
thin, repellent mass of slimy and decaying foliage. Calhoun bent down
to it.

It had a sour, faintly astringent smell of decay. These were the
ground-cover plants of Maya of which Calhoun had read. They had motile
stems, leaves and flowers, and they had cannibalistic tendencies. They
were the local weeds which made it impossible to grow grain for human
use upon this world.

And they were dead.

Calhoun straightened up and returned to the car. Plants like this were
wilted at the base of the spaceport building, and on another place
where there should have been sward. Calhoun had seen a large dead
member of the genus in a florist's, that had been growing in a cage
before it died. There was a singular coincidence here: humans ran away
from something, and something caused the death of a particular genus
of cannibal weeds.

It did not exactly add up to anything in particular, and certainly
wasn't evidence for anything at all. But Calhoun drove on in a vaguely
puzzled mood. The germ of a guess was forming in his mind. He couldn't
pretend to himself that it was likely, but it was surely no more
unlikely than most of a million human beings abandoning their homes at
a moment's notice.


III

They came to the turnoff for a town called Tenochitlan, some forty
miles from Maya City. Calhoun swung off the highway to go through it.

Whoever had chosen the name Maya for this planet had been interested
in the legends of Yucatan, back on Earth. There were many instances of
such hobbies in a Med Ship's list of ports of call. Calhoun touched
ground regularly on planets that had been named for countries and towns
when men first roamed the stars, and nostalgically christened their
discoveries with names suggested by homesickness. There was a Tralee,
and a Dorset, and an Eire. Colonists not infrequently took their
world's given name as a pattern and chose related names for seas and
peninsulas and mountain chains. On Texia the landing-grid rose near a
town called Corral and the principal meat-packing settlement was named
Roundup.

Whatever the name Tenochitlan would have suggested, though, was denied
by the town itself. It was small, with a pleasing local type of
architecture. There were shops and some factories, and many strictly
private homes, some clustered close together and others in the middles
of considerable gardens. In those gardens also there was wilt and decay
among the cannibal plants. There was no grass, because the plants
prevented it, but now the motile plants themselves were dead. Except
for the one class of killed growing things, however, vegetation was
luxuriant.

But the little city was deserted. Its streets were empty, its houses
untenanted. Some houses were apparently locked up here, though, and
Calhoun saw three or four shops whose stock in trade had been covered
over before the owners departed. He guessed that either this town had
been warned earlier than the spaceport city, or else they knew they had
time to get in motion before the highways were filled with the cars
from the west.

Allison looked at the houses with keen, evaluating eyes. He did not
seem to notice the absence of people. When Calhoun swung back on the
great road beyond the little city, Allison regarded the endless fields
of dark-green plants with much the same sort of interest.

"Interesting," he said abruptly when Tenochitlan fell behind and
dwindled to a speck. "Very interesting! I'm interested in land. Real
property, that's my business. I've a land-owning corporation on Thanet
Three. I've some holdings on Dorset, too, and elsewhere. It just
occurred to me: what's all this land and the cities worth, with the
people all run away?"

"What," asked Calhoun, "are the people worth who've run?"

Allison paid no attention. He looked shrewd. Thoughtful.

"I came here to buy land," he said. "I'd arranged to buy some hundreds
of square miles. I'd buy more if the price were right. But--as things
are, it looks like the price of land ought to go down quite a bit.
Quite a bit!"

"It depends," said Calhoun, "on whether there's anybody left alive to
sell it to you, and what sort of thing has happened."

Allison looked at him sharply.

"Ridiculous!" he said authoritatively. "There's no question of their
being alive!"

"They thought there might be," observed Calhoun. "That's why they ran
away. They hoped they'd be safe where they ran to. I hope they are."

Allison ignored the comment. His eyes remained intent and shrewd. He
was not bewildered by the flight of the people of Maya. His mind was
busy with contemplation of that flight from the standpoint of a man of
business.

       *       *       *       *       *

The car went racing onward. The endless fields of dark green rushed
past to the rear. The highway was deserted, just three strips of
surfaced road, mathematically straight, going on to the horizon. They
went on by tens and scores of miles, each strip wide enough to allow
four ground-cars to run side by side. The highway was intended to
allow all the produce of all these fields to be taken to market or a
processing plant at the highest possible speed and in any imaginable
quantity. The same roads had allowed the cities to be deserted
instantly the warning--whatever the warning was--arrived.

Fifty miles beyond Tenochitlan there was a mile-long strip of sheds
containing agricultural machinery for crop culture and trucks to carry
the crops to market. There was no sign of life about the machinery, nor
in a further hour's run to westward.

Then there was a city visible to the left. But it was not served
by this particular highway, but another. There was no sign of any
movement in its streets. It moved along the horizon to the left and
rear. Presently it disappeared.

Half an hour later still, Murgatroyd said:

"_Chee!_"

He stirred uneasily. A moment later he said "_Chee!_" again.

Calhoun turned his eyes from the road. Murgatroyd looked unhappy.
Calhoun ran his hand over the _tormal's_ furry body. Murgatroyd pressed
against him. The car raced on. Murgatroyd whimpered a little. Calhoun's
hand felt the little animal's muscles tense sharply, and then relax,
and after a little tense again. Murgatroyd said almost hysterically:

"_Chee-chee-chee-chee!_"

Calhoun stopped the car, but Murgatroyd did not seem to be relieved.
Allison said impatiently, "What's the matter?"

"That's what I'm trying to find out," said Calhoun.

He felt Murgatroyd's pulse. The role of Murgatroyd in the Med Ship
_Esclipus Twenty_ was not only that of charming companion in the long,
isolated runs in overdrive. Murgatroyd was a part of the Med Service.
His tribe had been discovered on a planet in the Deneb sector, and
men had made pets of them, to the high satisfaction of the _tormals_.
Presently it was discovered that veterinarians never had _tormals_
for patients. They were invariably in robustuous good health. They
contracted no infections from other animals; they shared no infections
with anybody else. The Med Service discovered that _tormals_ possessed
a dynamic immunity to germ and bacteria-caused diseases. Even
viruses injected into their bloodstreams only provoked an immediate,
overwhelming development of antibodies, so that _tormals_ couldn't be
given any known disease. Which was of infinite value to the Med Service.

Now every Med Ship that could be supplied with a _tormal_ carried a
small, affectionate, whiskered member of the tribe. Men liked them,
and they adored men. And when, as sometimes happened, by mutation or
the simple enmity of nature, a new kind of infection appeared in human
society--why--_tormals_ defeated it. They produced specific antibodies
to destroy it. Men analyzed the antibodies and synthesized them, and
they were available to all the humans who needed them. So a great many
millions of humans stayed alive, because _tormals_ were pleasant little
animals with a precious genetic gift of good health.

       *       *       *       *       *

Calhoun looked at his sweep-second watch, timing the muscular spasms
that Murgatroyd displayed. They coincided with irregularities in
Murgatroyd's heartbeat, coming at approximately two-second intervals.
The tautening of the muscles lasted just about half a second.

"But I don't feel it!" said Calhoun.

Murgatroyd whimpered again and said, "_Chee-chee!_"

"What's going on?" demanded Allison with the impatience of a very
important man indeed. "If the beast's sick, he's sick! I've got to
find--"

Calhoun opened his med kit and went carefully through it until he found
what he needed. He put a pill into Murgatroyd's mouth.

"Swallow it!" he commanded.

Murgatroyd resisted, but the pill went down. Calhoun watched him
sharply. Murgatroyd's digestive system was delicate, but it was
dependable. Anything that might be poisonous, Murgatroyd's stomach
rejected instantly and emphatically.

The pill stayed down.

"Look!" said Allison indignantly. "I've got business to do! In this
attache case I have millions of interstellar credits, in cash, to pay
down on purchases of land and factories. I ought to make some damned
good deals! And I figure that that's as important as anything else you
can think of! It's a damned sight more important than a beast with a
belly-ache!"

Calhoun looked at him coldly.

"Do you own land on Texia?" he asked.

Allison's mouth dropped open. Extreme suspicion and unease appeared
on his face. As a sign of the unease, his hand went to the side coat
pocket in which he'd put a blaster. He didn't pluck it out. Calhoun's
left fist swung around and landed. He took Allison's elaborate pocket
blaster and threw it away among the monotonous rows of olive-green
plants. He returned to absorbed observation of Murgatroyd.

In five minutes the muscular spasms diminished. In ten, Murgatroyd
frisked. But he seemed to think that Calhoun had done something
remarkable. In the warmest of tones he said:

"_Chee!_"

"Very good," said Calhoun. "We'll go ahead. I suspect you'll do as well
as we do--for a while."

The car lifted the few inches the air columns sustained it above the
ground. It went on, still to the eastward. But Calhoun drove more
slowly now.

"Something was giving Murgatroyd rhythmic muscular spasms," he said
coldly. "I gave him medication to stop them. He's more sensitive than
we are, so he reacted to a stimulus we haven't noticed yet. But I
think we'll notice it presently."

Allison seemed to be dazed at the affront given him. It appeared to be
unthinkable that anybody might lay hands on him.

"What the devil has that to do with me?" he demanded angrily. "And what
did you hit me for? You're going to pay for this!"

"Until I do," Calhoun told him, "you'll be quiet. And it does have the
devil to do with you. There was a Med Service gadget once--a tricky
little device to produce contraction of chosen muscles. It was useful
for re-starting stopped hearts without the need of an operation.
It regulated the beat of hearts that were too slow or dangerously
irregular. But some businessman had a bright idea and got a tame
researcher to link that gadget to ground induction currents. I suspect
you know that businessman!"

"I don't know what you're talking about," snapped Allison. But he was
singularly tense.

"I do," said Calhoun unpleasantly. "I made a public health inspection
on Texia a couple of years ago. The whole planet is a single, gigantic,
cattle-raising enterprise. They don't use metal fences--the herds are
too big to be stopped by such things. They don't use cowboys--they cost
money. On Texia they use ground-induction and the Med Service gadget
linked together to serve as cattle fences. They act like fences, though
they're projected through the ground. Cattle become uncomfortable when
they try to cross them. So they draw back. So men control them. They
move them from place to place by changing the cattle fences, which
are currents induced in the ground. The cattle have to keep moving
or be punished by the moving fence. They're even driven into the
slaughterhouse chutes by ground-induction fields! That's the trick
on Texia, where induction fields herd cattle. I think it's the trick
on Maya, where people are herded like cattle and driven out of their
cities so the value of their fields and factories will drop,--so a land
buyer can find bargains!"

"You're insane!" snapped Allison. "I just landed on this planet! You
saw me land! I don't know what happened before I got here! How could I?"

"You might have arranged it," said Calhoun.

       *       *       *       *       *

Allison assumed an air of offended and superior dignity. Calhoun drove
the car onward at very much less than the head-long pace he'd been
keeping to. Presently he looked down at his hands on the steering
wheel. Now and then the tendons to his fingers seemed to twitch. At
rhythmic intervals, the skin crawled on the back of his hands. He
glanced at Allison. Allison's hands were tightly clenched.

"There's a ground-induction fence in action, all right," said Calhoun
calmly. "You notice? It's a cattle fence and we're running into it. If
we were cattle, now, we'd turn around and move away."

"I don't know what you're talking about!" said Allison.

But his hands stayed clenched. Calhoun slowed the car still more. He
began to feel, all over his body, that every muscle tended to twitch at
the same time. It was a horrible sensation. His heart muscles tended
to contract too, simultaneously with the rest, but one's heart has its
own beat rate. Sometimes the normal beat coincided with the twitch.
Then his heart pounded violently--so violently that it was painful. But
equally often the imposed contraction of the heart muscles came just
after a normal contraction, and then it stayed tightly knotted for half
a second. It missed a beat, and the feeling was agony.

No animal would have pressed forward in the face of such sensations. It
would have turned back long ago. No animal. Not even Man.

Calhoun stopped the car. He looked at Murgatroyd. Murgatroyd was
completely himself. He looked inquiringly at Calhoun. Calhoun nodded to
him, but he spoke--with some difficulty--to Allison.

"We'll see--if this thing--builds up. You know that it's the
Texia--trick. A ground-induction unit set up--here. It drove
people--like cattle. Now we've--run into it.--It's holding people--like
cattle."

He panted. His chest muscles contracted with the rest, so that his
breathing was interfered with. But Murgatroyd, who'd been made uneasy
and uncomfortable before Calhoun noticed anything wrong, was now
bright and frisky. Medication had desensitized his muscles to outside
stimuli. He would be able to take a considerable electric shock without
responding to it.

But he could be killed by one that was strong enough.

A savage anger filled Calhoun. Everything fitted together. Allison
had put his hand convenient to his blaster when Calhoun mentioned
Texia. It meant that Calhoun suspected what Allison knew to be true.
A cattle-fence unit had been set up on Maya, and it was holding--like
cattle--the people it had previously driven--like cattle. Calhoun
could deduce with some precision exactly what had been done. The first
experience of Maya with the cattle fence would have been very mild.
It would have been low-power, causing just enough uneasiness to be
noticed. It would have moved from west to east, slowly, and it would
have reached a certain spot and there faded out. And it would have been
a mystery and an uncomfortable thing, and nobody would understand it
on Maya. In a week it would almost be forgotten. But then there'd come
a stronger disturbance. And it would travel like the first one; down
the length of the peninsula on which the colony lay, but stopping at
the same spot as before, and then fading away to nothingness. And this
also would have seemed mysterious. But nobody would suspect humans of
causing it. There would be theorizing and much questioning, but it
would be considered an unfamiliar natural event.

Probably the third use of the cattle fence would be most disturbing.
This time it would be acutely painful. But it would move into the
cities and through them and past them, and it would go down the
peninsula to where it had stopped and faded on two previous occasions.

The people of Maya would be disturbed and scared. But they considered
that they knew it began to the westward of Maya City, and moved toward
the east at such-and-such a speed, and it went so far and no farther.
And they would organize themselves to apply this carefully worked out
information.

It would not occur to any of them that they had learned how to be
driven like cattle.

       *       *       *       *       *

Calhoun, of course, could only reason that this must have happened. But
nothing else could have taken place. Perhaps there were more than three
uses of the moving cattle fence to get the people prepared to move past
the known place at which it always faded to nothingness. They might
have been days apart, or weeks apart, or months. There might have been
stronger manifestations followed by weaker ones and then stronger ones
again.

But there was an inductive cattle fence across the highway here.
Calhoun had driven into it. Every two seconds the muscles of his
body tensed. Sometimes his heart missed a beat at the time that his
breathing stopped, and sometimes it pounded violently. It seemed that
the symptoms became more and more unbearable.

He got out his med kit, with hands that spasmodically jerked
uncontrollably. He fumbled out the same medication he'd given
Murgatroyd. He took two of the pellets.

"In reason," he said coldly, "I ought to let you take what this damned
thing would give you. But--here!"

Allison had panicked. The _idea_ of a cattle fence suggested
discomfort, of course, but it did not imply danger. The _experience_
of a cattle fence, designed for huge hoofed beasts instead of men,
was terrifying. Allison gasped. He made convulsive movements. Calhoun
himself moved erratically. For one and a half seconds out of two, he
could control his muscles. For half a second at a time, he could not.
But he poked a pill into Allison's mouth.

"Swallow it!" he commanded. "Swallow!"

The ground-car rested tranquilly on the highway, which here went on for
a mile and then dipped in a gentle incline and then rose once more.
The totally level fields to right and left came to an end here. Native
trees grew, trailing preposterously with long fronds. Brushwood hid
much of the ground. That looked normal. But the lower, ground-covering
vegetation was wilted and rotting.

Allison choked upon the pellet. Calhoun forced a second upon him.
Murgatroyd looked inquisitively at first one and then the other of the
two men. He said:

"_Chee? Chee?_"

Calhoun lay back in his seat, breathing carefully to keep alive. But
he couldn't do anything about his heartbeat. The sun shone brightly,
though now it was low, toward the horizon. There were clouds in the
reddened sky. A gentle breeze blew. Everything, to outward appearance,
was peaceful and tranquil and commonplace upon this small world.

But in the area that human beings had taken over there
were cities which were still and silent and deserted, and
somewhere--somewhere!--the population of the planet waited uneasily for
the latest of a series of increasingly terrifying phenomena to come to
an end. Up to this time the strange, creeping, universal affliction had
begun at one place, and moved slowly to another, and then diminished
and ceased to be. But this was the greatest and worst of the torments.
And it hadn't ended. It hadn't diminished. After three days it
continued at full strength at the place where previously it had stopped
and died away.

The people of Maya were frightened. They couldn't return to their
homes. They couldn't go anywhere. They hadn't prepared for an emergency
to last for days. They hadn't brought supplies of food.

It began to look as if they were going to starve.


IV

Calhoun was in very bad shape when the sports car came to the end of
the highway.

First, all the multiple roadways of the route that had brought him here
were joined by triple ribbons of road-surface from the north. For a
space there were twenty-four lanes available to traffic. They flowed
together, and then there were twelve. Here there was evidence of an
enormous traffic concentration at some time now past. Brush and small
trees were crushed and broken where cars had been forced to travel
off the hard-surface roadways and through undergrowth. The twelve
lanes dwindled to six, and the unpaved area on either side showed that
innumerable cars had been forced to travel off the highway altogether.
Then there were three lanes, and then two, and finally only a single
ribbon of pavement where no more than two cars could run side by side.
The devastation on either hand was astounding. All visible vegetation
for half a mile to right and left was crushed and tangled. And then the
narrow surfaced road ceased to be completely straight. It curved around
a hillock--and here the ground was no longer perfectly flat--and came
to an end.

And Calhoun saw all the ground-cars of the planet gathered and parked
together.

There were no buildings. There were no streets. There was nothing of
civilization but tens and scores of thousands of ground-cars. They were
extraordinary to look at, stopped at random, their fronts pointed in
all directions, their air-column tubes thrusting into the ground so
that there might be trouble getting them clear again.

Parked bumper to bumper in closely placed lines, in theory twenty-five
thousand cars could be parked on a square mile of ground. But there
were very many times that number of cars here, and some places were
unsuitable for parking, and there were lanes placed at random and
there'd been no special effort to put the maximum number of cars in
the smallest place. So the surface transportation system of the planet
Maya spread out over some fifty sprawling square miles. Here, cars were
crowded closely. There, there was much room between them. But it seemed
that as far as one could see in the twilight there were glistening
vehicles gathered confusedly, so there was nothing else to be seen but
an occasional large tree rising from among them.

Calhoun came to the end of the surfaced road. He'd waited for the
pellets he'd taken and given to Allison to have the effect they'd had
on Murgatroyd. That had come about. He'd driven on. But the strength of
the inductor field had increased to the intolerable. When he stopped
the sports car he showed the effects of what he'd been through.

Figures on foot converged upon him instantly. There were eager calls.

"It's stopped? You got through? We can go back?"

Calhoun shook his head. It was just past sunset and many brilliant
colorings showed in the western sky, but they couldn't put color into
Calhoun's face. His cheeks were grayish and his eyes were deep-sunk,
and he looked like someone in the last stages of exhaustion. He said
heavily:

"It's still there. We came through. I'm Med Service. Have you got a
government here? I need to talk to somebody who can give orders."

       *       *       *       *       *

If he'd asked two days earlier there would have been no answer, because
the fugitives were only waiting for a disaster to come to an end. One
day earlier, he might have found men with authority busily trying to
arrange for drinking water for something like two millions of people,
in the entire absence of wells or pumps or ways of making either.
And if he'd been a day later, it is rather likely that he'd have
found savage disorder. But he arrived at sundown three days after the
flight from the cities. There was no food to speak of, and water was
drastically short, and the fugitives were only beginning to suspect
that they would never be able to leave this place--and that they might
die here.

Men left the growing crowd about the sports car to find individuals
who could give orders. Calhoun stayed in the car, resting from the
unbearable strain he'd undergone. The ground-inductor cattle fence
had been ten miles deep. One mile was not bad. Only Murgatroyd had
noticed it. After two miles Calhoun and Allison suffered; but the
medication strengthened them to take it. But there'd been a long, long
way in the center of the induction-field in which existence was pure
torment. Calhoun's muscles defied him for part of every two-second
cycle, and his heart and lungs seemed constantly about to give up even
the pretense of working. In that part of the cattle-fence field, he'd
hardly dared drive faster than a crawl, in order to keep control of
the car when his own body was uncontrollable. But presently the field
strength lessened and ultimately ended.

Now Murgatroyd looked cordially at the figures who clustered about
the car. He'd hardly suffered at all. He'd had half as much of the
medication as Calhoun himself, and his body weight was only a tenth
of Calhoun's. He'd made out all right. Now he looked expectantly at
what became a jammed mass of crowding men about the vehicle that had
come through the invisible barrier across the highway. They hoped
desperately for news to produce hope. But Murgatroyd waited zestfully
for somebody to welcome him and offer him cakes and sweets, and
undoubtedly presently a cup of coffee.

But nobody did.

It was a long time before there was a stirring at the edge of the
crowd. Night had fully fallen then, and for miles and miles in all
directions lights in the ground cars of Maya's inhabitants glowed
brightly. They drew upon broadcast power, naturally, for their motors
and their lights. Off to one side someone shouted. Calhoun turned on
his headlights for a guide. More shoutings. A knot of men struggled to
get through the crowd. With difficulty, presently, they reached the car.

"They say you got through," panted a tall man, "but you can't get back.
They say--"

Calhoun roused himself. Allison, beside him, stirred. The tall man
panted again:

"I'm the planetary president. What can we do?"

"First, listen," said Calhoun tiredly.

He'd had a little rest. Not much, but some. The actual work he'd done
in driving three hundred-odd miles from Maya City was trivial. But
the continuous, and lately violent, spasms of his heart and breathing
muscles had been exhausting. He heard Murgatroyd say ingratiatingly,
"_Chee-chee-chee-chee_," and put his hand on the little animal to quiet
him.

"The thing you ran away from," said Calhoun with effort, "is a type of
ground-induction field using broadcast power from the grid. It's used
on Texia to confine cattle to their pastures and to move them where
they're wanted to be. But it was designed for cattle. It's a cattle
fence. It could kill humans."

       *       *       *       *       *

He went on, his voice gaining strength and steadiness as he spoke. He
explained, precisely, how a ground-induction field was projected in a
line at a right angle to its source. It could be moved by adjustments
of the apparatus by which it was projected.

"But--but if it uses broadcast power," the planetary president said
urgently, "then if the power broadcast is cut off it has to stop!
If you got through it coming here, tell us how to get through going
back and we'll cut off the power broadcast ourselves! We've got to
do something immediately. The whole planet's here. There's no food!
There's no water! Something has to be done before we begin to die!"

"But," said Calhoun, "if you cut off the power you'll die anyway!
You've got a couple of million people here, and you're a hundred miles
from food. Without power you couldn't get to food or bring it here. Cut
the power and you're still stranded here. Without power you'll die as
soon as with it."

There was a sound from the listening men around. It was partly a growl
and partly a groan.

"I've just found this out," said Calhoun. "I didn't know until the last
ten miles exactly what the situation was, and I had to come here to be
sure. Now I need some people to help me. It won't be pleasant. I may
have enough medication to get a dozen people back through. It'll be
safer if I take only six. Get a doctor to pick me six men. Good heart
action. Sound lungs. Two should be electronics engineers. The others
should be good shots. If you get them ready, I'll give them the same
stuff that got us through. It's desensitizing medication, but it will
do only so much. And try and find some weapons for them."

Voices murmured all around. Men hastily explained to other men what
Calhoun had said. The creeping disaster before which they'd all
fled,--it was not a natural catastrophe, but an artificial one! Men
had made it! They'd been herded here and their wives and children were
hungry because of something men had done!

A low-pitched, buzzing, humming sound came from the crowd about the
sports car. For the moment, nobody asked what could be the motive for
men to do what had been done. Pure fury filled the mob. Calhoun leaned
closer to Allison.

"I wouldn't get out of the car if I were you," he said in a low tone.
"I certainly wouldn't try to buy any real property at a low price!"

Allison shivered. There was a vast, vast stirring as the explanation
passed from man to man. Figures moved away in the darkness. Lighted
car windows winked as they moved through the obscurity. The population
of Maya was spread out over very many square miles of what had been
wilderness, and there was no elaborate communication system by which
information could be spread quickly. But long before dawn there'd be
nobody who didn't know that they'd fled from a man-made danger and were
held here like cattle, behind a cattle fence, apparently abandoned to
die.

       *       *       *       *       *

Allison's teeth chattered. He was a business man and up to now he'd
thought as one. He'd made decisions in offices, with attorneys and
secretaries and clerks to make the decisions practical and safe,
without any concern for any consequences other than financial ones.

He saw possible consequences to himself, here and now. He'd landed on
Maya because he considered the matter too important to trust to anybody
else. Even riding with Calhoun on the way here, he'd only been elated
and astonished at the success of the intended coup. He'd raised his
aim. For a while he'd believed that he'd end as the sole proprietor
of the colony on Maya, with every plant growing for his profit, and
every factory earning money for him, and every inhabitant his employee.
It had been the most grandiose possible dream. The details and the
maneuvers needed to complete it flowed into his mind.

But now his teeth chattered. At ten words from Calhoun he would
literally be torn to pieces by the raging men about him. His attache
case with millions of credits in cash--it would be proof of whatever
Calhoun chose to say. Allison knew terror down to the bottom of his
soul. But he dared not move from Calhoun's side, even though a single
sentence in the calmest of voices would destroy him, and he'd never
faced actual, understood, physical danger before.

Presently men came, one by one, to take orders from Calhoun. They were
able-bodied and grim-faced men. Two were electronics engineers, as he'd
specified. One was a policeman. There were two mechanics and a doctor
who was also amateur tennis champion of the planet. Calhoun doled
out to them the pellets that reduced the sensitiveness of muscles to
externally applied stimuli. He gave instructions. They'd go as far into
the cattle fence as they could reasonably endure. Then they'd swallow
the pellets and let them act. Then they'd go on. His stock of pellets
was limited. He could give three to each man.

Murgatroyd squirmed disappointedly as this briefing went on. Obviously,
he wasn't to make a social success here. He was annoyed, and he needed
more space. Calhoun tossed Allison's attache case behind the seats.
Allison was too terrified to protest. It still did not increase the
space left on the front seat between Calhoun and Allison.

Four humming ground cars lifted eight inches off the ground and hovered
there on columns of rushing air. Calhoun took the lead. His headlights
moved down the single-lane road to which two joining twelve-lane
highways had shrunk. Behind him, other headlights moved into line.
Calhoun's car moved away into the darkness. The others followed.

Brilliant stars shone overhead. A cluster of thousands of suns, a
hundred light-years away, made a center of illumination that gave
Maya's night the quality of a vivid if diffused moonlight. The cars
went on. Presently Calhoun felt the twitchings of minor muscular
spasms. He was riding into the field which had been first devised for
purposes remote from the herding of cattle or humans, but applied to
the first use on the planet Texia, and now applied to the second here.

The road became two, and then four, and then eight lanes wide. Then
four lanes swirled off to one side, and the remaining four presently
doubled, and then widened again, and it was the twelve-lane turnpike
that had brought Calhoun here from Maya City.

       *       *       *       *       *

But the rhythmic interference with his body grew stronger. Allison had
spoken not one single word while Calhoun conferred with the people of
Maya beyond the highway. His teeth chattered as they started back. He
didn't attempt to speak during the beginning of the ride through the
cattle-fence field. His teeth chattered, and stopped, and chattered
again, and at long last he panted despairingly:

"Are you going to let the thing kill me?"

Calhoun stopped. The cars behind him stopped. He gave Allison two
pellets and took two himself. With Murgatroyd insistently accompanying
him, he went along the cars which trailed him. He made sure the six men
he'd asked for took their pellets and that they had an adequate effect.
He went back to the sports car.

Allison whimpered a little when he and Murgatroyd got back in.

"I thought," said Calhoun conversationally, "that you might try to take
off by yourself, just now. It would solve a problem for me. Of course
it wouldn't solve any for you. But I don't think your problems have any
solution, now."

He started the car up again. It moved forward. The other cars trailed
dutifully. They went on through the starlit night. Calhoun noted that
the effect of the cattle fence was less than it had been before. The
first desensitizing pellets had not wholly lost their effect when he
added to it. But he kept his speed low until he was certain the other
drivers had endured the anguish of passing through the cattle-fence
field.

Presently he was confident that the cattle field was past. He sent his
car up to eighty miles an hour. The other cars followed faithfully. To
a hundred. They did not drop behind. The car hummed through the night
at top speed--a hundred and twenty, a hundred and thirty miles an hour.
The three other cars' headlights faithfully kept pace with him.

Allison, said desperately, "Look! I--don't understand what's happened.
You talk as if I'd planned all this. I--did have advance notice of a--a
research project here. But it shouldn't have held the people there for
days! Something went wrong! I only believed that people would want to
leave Maya. I'd only planned to buy as much acreage as I could, and
control of as many factories as possible. That's all! It was business!
Only business!"

Calhoun did not answer. Allison might be telling the truth. Some
businessmen would think it only intelligent to frighten people into
selling their holdings below true value. Something of the sort happened
every day in stock exchanges. But the people of Maya could have died!

For that matter, they still might. They couldn't return to their homes
and food so long as broadcast power kept the cattle-fence in existence.
But they could not return to their homes and food supplies if the power
broadcast was cut off, either.

Over all the night surface of the world of Maya there was light only
on one highway at one spot, and a multitude of smaller, lesser lights
where the people of Maya waited to find out whether they would live or
die.


V

Calhoun considered coldly. They were beyond what had been the
farthest small city on the multiple highway. They would go on past
now-starlit fields of plants native to Maya, passing many places where
trucks loaded with the plants climbed up to the roadway and headed
for the factories which made use of them. The fields ran for scores
of miles along the highway's length. They reached out beyond the
horizon,--perhaps scores of miles in that direction, too. There were
thousands upon thousands of square miles devoted to the growing of the
dark-green vegetation which supplied the raw materials for Maya's space
exports. Some hundred-odd miles ahead, the small town of Tenochitlan
lay huddled in the light of the distant star-cluster. Beyond that, more
highway and Maya City. Beyond that--

Calhoun reasoned that the projector to make the induction cattle fence
would be beyond Maya City, somewhere in the mountains the photograph
in the spaceport building showed. A large highway went into those
mountains for a limited distance only.

A ground-inductor projector field always formed at a right angle to
the projector which was its source. It could be adjusted--the process
was analogous to focusing--to come into actual being at any distance
desired, and the distance could be changed. To drive the people of
Maya City eastward, the projector of a cattle fence--about which
they would know nothing; it would be totally strange and completely
mysterious--the projector of the cattle fence would need to be west of
the people to be driven. Logically, it would belong in the mountains.
Practically, it would be concealed. Drawing on broadcast power to do
its work, there would be no large power source needed to give it the
six million kilowatts it required. It should be quite easy to hide
beyond any quick or easy discovery. Hunting it out might require weeks
of searching.

But the people beyond the end of the highway couldn't wait. They had
no food, and holes scrabbled down to ground-water by men digging with
their bare hands simply would not be adequate. The cattle fence had
to be cut off immediately--while the broadcast of power had to be
continued.

Calhoun made an abrupt grunting noise. Phrasing the thing that needed
to be done was practically a blueprint of how to do it. Simple! He'd
need the two electronics engineers, of course. But that would be the
trick....

He drove on at a hundred thirty miles an hour with his lips set wrily.
The three other cars came behind him. Murgatroyd watched the way ahead.
Mile after mile, half-minute after half-minute, the headlights cast
brilliantly blinding beams before the cars. Murgatroyd grew bored. He
said, "_Chee!_" in a discontented fashion and tried to curl up between
Allison and Calhoun. There wasn't room. He crawled over the seat-back.
He moved about, back there. There were rustling sounds. He settled
down. Presently there was silence. Undoubtedly he had draped his furry
tail across his nose and gone soundly off to sleep.

Allison spoke suddenly. He'd had time to think, but he had no practice
in various ways of thinking.

"How much money have you got?" he asked.

"Not much," said Calhoun. "Why?"

"I--haven't done anything illegal," said Allison, with an unconvincing
air of confidence, "but I could be put to some inconvenience if you
were to accuse me before others of what you've accused me personally.
You seem to think that I planned a criminal act. That the action I know
of--the research project I'd heard of--that it became--that it got out
of hand is likely. But I am entirely in the clear. I did nothing in
which I did not have the advice of counsel. I am legally unassailable.
My lawyers--"

       *       *       *       *       *

"That's none of my business," Calhoun told him. "I'm a medical man.
I landed here in the middle of what seemed to be a serious public
health situation. I went to see what had happened. I've found out. I
still haven't the answer,--not the whole answer anyway. But the human
population of Maya is in a state of some privation, not to say danger.
I hope to end it. But I've nothing to do with anybody's guilt or
innocence of crime or criminal intent or anything else."

Allison swallowed. Then he said with smooth confidence:

"But you could cause me inconvenience. I would appreciate it if you
would--would--"

"Cover up what you've done?" asked Calhoun.

"No! I've done nothing wrong. But you could simply use discretion. I
landed by parachute to complete some business deals I'd arranged months
ago. I will go through with them. I will leave on the next ship.
That's perfectly open and above board. Strictly business. But you could
make a--an unpleasing public image of me. Yet I have done nothing any
other business man wouldn't do! I did happen to know of a research
project--"

"I think," said Calhoun without heat, "that you sent men here with a
cattle-fence device from Texia to frighten the people on Maya. They
wouldn't know what was going on. They'd be scared; they'd want to get
away. So you'd be able to buy up practically all the colony for the
equivalent of peanuts. I can't prove that," he conceded, "but that's my
opinion. But you want me not to state it. Is that right?"

"Exactly!" said Allison. He'd been shaken to the core, but he managed
the tone and the air of a dignified man of business discussing an
unpleasant subject with fine candor. "I assure you you are mistaken.
You agree that you can't prove your suspicions. If you can't prove
them, you shouldn't state them. That is simple ethics. You agree to
that!"

Calhoun looked at him curiously.

"Are you waiting for me to tell you my price?"

"I'm waiting," said Allison reprovingly, "for you to agree not to cause
me embarrassment. I won't be ungrateful. After all, I'm a person of
some influence. I could do a great deal to your benefit. I'd be glad--"

"Are you working around to guess at a price I'll take?" asked Calhoun
with the same air of curiosity.

He seemed much more curious than indignant, and much more amused
than curious. Allison sweated suddenly. Calhoun didn't appear to be
bribable. But Allison knew desperation.

"If you want to put it that way--yes," he said harshly. "You can name
your own figure. I mean it!"

"I won't say a word about you," said Calhoun. "I won't need to. The
characters who're operating your cattle fence will do all the talking
that's necessary. Things all fit together,--except for one item.
They've been dropping into place all the while we've been driving down
this road."

"I said you can name your own figure!" Allison's voice was shrill. "I
mean it! Any figure! Any!"

Calhoun shrugged.

"What would a Med Ship man do with money? Forget it!"

He drove on. The highway turnoff to Tenochitlan appeared. Calhoun went
steadily past it. The other connection with the road through the town
appeared. He left it behind.

Allison's teeth chattered again.

The buildings of Maya City began to appear, some twenty minutes later.
Calhoun slowed and the other cars closed up. He opened a window and
called:

"We want to go to the landing-grid first. Somebody lead the way!"

A car went past and guided the rest assuredly to a ramp down from the
now-elevated road, and through utterly dark streets, of which some were
narrow and winding, and came out abruptly where the landing-grid rose
skyward. At the bottom its massive girders looked huge and cyclopean in
the starlight, but the higher courses looked like silver lace against
the stars.

       *       *       *       *       *

They went to the control building. Calhoun got out. Murgatroyd hopped
out after him, dust clinging to his fur. He shook himself, and a
ten-thousand-credit interstellar credit certificate fell to the ground.
Murgatroyd had made a soft place for sleeping out of the contents of
Allison's attache case. It was assuredly the most expensive if not the
most comfortable sleeping cushion a _tormal_ ever had. Allison sat
still as if numbed. He did not even pick up the certificate.

"I need you two electronics men," said Calhoun. Then he said
apologetically to the others, "I only figured out something on the way
here. I'd believed we might have to take some drastic action, come
daybreak. But now I doubt it. I do suggest, though, that you turn off
the car headlights and get set to do some shooting if anybody turns up.
I don't know whether they will or not."

He led the way inside. He turned on lights. He went to the place where
dials showed the amount of power actually being used of the enormous
amount available. Those dials now showed an extremely small power
drain, considering that the cities of a planet depended on the grid.
But the cities were dark and empty of people. The demand needle wavered
back and forth, rhythmically. Every two seconds the demand for power
went up by six million kilowatts, approximately. The demand lasted for
half a second, and stopped. For a second and a half the power in use
was reduced by six million kilowatts. During this period only automatic
pumps and ventilators and freezing equipment drew on the broadcast
power for energy. Then the six-million-kilowatt demand came again for
half a second.

"The cattle fence," said Calhoun, "works for half a second out of every
two seconds. It's intermittent or it would simply paralyze animals
that wandered into it. Or people. Being intermittent, it drives them
out instead. There'll be tools and parts for equipment here, in case
something needs repair. I want you to make something new."

The two electronics technicians asked questions.

"We need," said Calhoun, "an interruptor that will cut off the power
broadcast for the half-second the ground-induction field is supposed
to be on. Then it should turn on the broadcast power for the second
and a half the cattle fence is supposed to be off. That will stop the
cattle-fence effect, and I think a ground car should be able to work
with power that's available for three half-seconds out of four."

The electronics men blinked at him. Then they grinned and set to work.
Calhoun went exploring. He found a lunch box in a desk with three very
stale sandwiches in it. He offered them around.

It appeared that nobody wanted to eat while their families--at the end
of the highway--were still hungry.

The electronics men called on the two mechanics to help build
something. They explained absorbedly to Calhoun that they were making
a cutoff which would adjust to any sudden six-million-kilowatt demand,
no matter what time interval was involved. A change in the tempo of the
cattle-fence cycle wouldn't bring it back on.

"That's fine!" said Calhoun. "I wouldn't have thought of that!"

He bit into a stale sandwich and went outside. Allison sat limply,
despairingly, in his seat in the car.

"The cattle fence is going off," said Calhoun without triumph. "The
people of the city will probably begin to get here around sunrise."

"I--I did nothing legally wrong!" said Allison, dry-throated. "Nothing!
They'd have to prove that I knew what the--consequences of the research
project would be. That couldn't be proved! It couldn't! So I've done
nothing legally wrong...."

Calhoun went inside, observing that the doctor who was also tennis
champion, and the policeman who'd come to help him, were keeping keen
eyes on the city and the foundations of the grid and all other places
from which trouble might come.

There was a fine atmosphere of achievement in the power-control
room. The power itself did not pass through these instruments, but
relays here controlled buried massive conductors which supplied the
world with power. And one of the relays had been modified. When the
cattle-fence projector closed its circuit, the power went off. When
the ground-inductor went off, the power went on. There was no longer
a barrier across the highways leading to the east. It was more than
probable that ground cars could run on current supplied for one and a
half seconds out of every two. They might run jerkily, but they would
run.

       *       *       *       *       *

Half an hour later, the amount of power drawn from the broadcast began
to rise smoothly and gradually. It could mean only that cars were
beginning to move.

Forty-five minutes later still, Calhoun heard stirrings outside. He
went out. The two men on guard gazed off into the city. Something moved
there. It was a ground-car, running slowly and without lights. Calhoun
said undisturbedly:

"Whoever was running the cattle fence found out their gadget wasn't
working. Their lights flickered, too. They came to see what was the
matter at the landing-grid. But they've seen the lighted windows. Got
your blasters handy?"

But the unlighted car turned and raced away. Calhoun only shrugged.

"They haven't a prayer," he said. "We'll take over their apparatus
as soon as it's light. It'll be too big to destroy, and there'll be
fingerprints and such to identify them as the men who ran it. And
they're not natives. When the police start to look for the strangers
who were living where the cattle-fence projector was set up.... They
can go into the jungles where there's nothing to eat, or they can give
themselves up."

He moved toward the door of the control building once more. Allison
said desperately:

"They'll have hidden their equipment. You'll never be able to find it!"

Calhoun shook his head in the starlight.

"Anything that can fly can spot it in minutes. Even on the ground
one can walk almost straight to it. You see, something happened they
didn't count on. That's why they've left it turned on at full power.
The earlier, teasing uses of the cattle fence were low-power. Annoying,
to start with, and uncomfortable the second time, and maybe somewhat
painful the third. But the last time it was full power."

He shrugged. He didn't feel like a long oration. But it was obvious.
Something had killed the plants of a certain genus of which small
species were weeds that destroyed Earth-type grasses. The ground-cover
plants--and the larger ones, like the one Calhoun had seen decaying
in a florist's shop which had had to be grown in a cage--the
ground-cover plants had motile stems and leaves and blossoms. They
were cannibals. They could move their stems to reach, and their
leaves to enclose, and their flowers to devour other plants, even
perhaps small animals. The point, though, was that they had some
limited power of motion. Earth-style sensitive vines and flycatcher
plants had primitive muscular tissues. The local ground-cover plants
had them too. And the cattle-fence field made those tissues contract
spasmodically. Powerfully. Violently. Repeatedly. Until they died of
exhaustion. The full-power cattle-fence field had exterminated Mayan
ground-cover plants all the way to the end of the east-bound highway.
And inevitably--and very conveniently--also up to the exact spot where
the cattle-fence field had begun to be projected. There would be an
arrow-shaped narrowing of the wiped-out ground-cover plants where the
cattle-field had been projected. It would narrow to a point which
pointed precisely to the cattle-fence projector.

"Your friends," said Calhoun, "will probably give themselves up and ask
for mercy. There's not much else they can do."

Then he said:

"They might even get it. D'you know, there's an interesting side effect
of the cattle fence. It kills the plants that have kept Earth-type
grasses from growing here. Wheat can be grown here now, whenever and
as much as the people please. It should make this a pretty prosperous
planet, not having to import all its bread."

       *       *       *       *       *

The ground cars of the inhabitants of Maya City did begin to arrive at
sunrise. Within an hour after daybreak, very savagely intent persons
found the projector and turned it off.

By noon there was still some anger on the faces of the people of Maya,
but there'd been little or no damage, and life took up its normal
course again. Murgatroyd appreciated the fact that things went back to
normal. For him it was normal to be welcomed and petted when the Med
Ship _Esclipus Twenty_ touched ground. It was normal for him to move
zestfully in admiring human society, and to drink coffee with great
gusto.

And while Murgatroyd moved in human society, enjoying himself hugely,
Calhoun went about his business. Which, of course, was conferences with
planetary health officials, politely receiving such information as they
thought important, and tactfully telling them about the most recent
developments in medical science.

What else was a Med Ship man for?