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                            CHAIN REACTION

                            By BOYD ELLANBY

                         Illustrated by DOKTOR

           [Transcriber's Note: This etext was produced from
                Galaxy Science Fiction September 1956.
         Extensive research did not uncover any evidence that
         the U.S. copyright on this publication was renewed.]




              Would this be the last poker game--with all
              life at stake and every card a mere deuce?


MacPherson shuffled the cards over and over again. His hands were
almost steady.

"Want to place a limit on the bets?" he asked.

His two colleagues who had made the night drive with him from the
University said nothing, but Rothman laughed.

"Today?" he said. "Today, the sky's the limit."

MacPherson rested the deck on the table and watched as Rothman stood
up to look through the barred window at the glittering Arizona desert.
Rothman had got thinner during his months of confinement; his shoulders
were bony beneath the gray hospital robe and his balding head looked
like a skull.

"Are you going to play?" asked MacPherson. "Or is poker too childish an
amusement for a mathematician?"

Rothman turned his back to the window. "Oh, I'll play. When three old
friends from the Project suddenly turn up for a visit, even a madman
will string along."

Shuffling the cards again, MacPherson wished the other men would say
something; it wasn't fair of them to make him carry the conversation.
Professor Avery, who had cut his physics classes in order to join the
morning's party, sat in glum silence. His plump face was pale, and
behind thick-lensed spectacles which enlarged his eyes grotesquely, he
blinked as he watched the flickering cards. Dr. Neill, from Physical
Chemistry, was tapping his toe against the table leg, watching Rothman,
who stood at the window, waiting.

"But we can't have much of a game with only four people," said Rothman.
"We ought to have a fifth."

"Maybe we can find someone." MacPherson walked to the locked steel door
and rattled the rectangular lattice set in at shoulder height, put his
mouth to the metal bars and called out.

"Hey, Joe!"

       *       *       *       *       *

An attendant in white uniform shuffled into the corridor of closed
doors, carrying a tray with one hand and scratching his head with the
other.

"How about joining us for a game of poker?"

Joe shook his head and grinned. "Not me, Professor! I start buddying
around with the loonies, I lose my job."

"But we're not inmates!"

"Maybe not, but Dr. Rothman is."

"Doesn't prove I'm crazy, Joe," said Rothman. "Conversely, not being
inmates doesn't prove these men are sane."

"It's a fact you don't look any crazier to me than a lot of
professors," confessed Joe. "I don't know. All I know is, _I'm_
not crazy enough to break the rules and lose my job. Besides, you
long-hairs wouldn't stand a chance at poker with me."

Still grinning, he shuffled out of sight down the hall.

MacPherson sighed and went back to the table. "Well, we'll have to get
along with just the four of us."

"There's always the unseen guest," said Rothman, "but you won't need to
deal him a hand. He already holds all the cards."

Neill looked up. "Stop hamming and sit down. Quit making like a maniac.
It's not even a good act."

"Okay." Rothman drew up a chair. "Now what was said about limiting the
bets?"

"Why bother setting a limit?" said Neill. "We're not likely to mistake
each other for millionaires and we all got exactly the same pay when we
were on the Project. Unless your sick pay has had two or three zeros
tacked onto it, you're not going to be making any wild bets, and as for
the rest of us--"

"University professors are still being paid less than nightclub
dancers," said Avery. "You're lucky to be out of the rat race,
Rothman. While we worry about how to pay the grocery bill, you can
relax, eating and sleeping at government expense. You never had it so
good."

"Maybe you'd like to get yourselves committed and keep me company?"

MacPherson rapped the deck on the table. "Stop that kind of talk. We
came here to play poker."

"Did you?" asked Rothman, grinning. "Then why don't you deal?"

"Cut, Neill?" said MacPherson. As he shot the slippery cards over the
table top, each flick of his thumb watched by Rothman's intent eyes,
he regretted this impulsive visit; it now seemed a gesture without
meaning. He wondered whether the others were as nervous as he was.

On the drive over from Los Angeles during the night, Neill had seemed
calm enough and even Avery, who had changed a lot during work on the
Project, had chatted with them unconstrainedly. It was hard to be
certain what other men were feeling, even when you had known them a
long time, but it could not be pleasant for any of them to be visiting
a former colleague who had been removed from the Project directly to a
sanitarium.

"Tell me something," said Rothman as he picked up his cards. "Do you
still think I'm crazy?"

"Don't be an idiot," MacPherson snapped. "Do you think we'd cut our
classes and drive nearly five hundred miles just to play poker with a
lunatic?"

"No," said Rothman. "That's how I know. But why aren't you frank about
it? Why keep on pretending there wasn't a special reason for your
visit?"

       *       *       *       *       *

Neill was beating his foot against the table leg again and Avery's eyes
were hard and staring as he examined his cards.

"Who'll open?" MacPherson asked. "I can't."

"I can," said Rothman. "I'm betting one blue chip. Listen, Avery, why
won't you look at me? If you think I'm hamming, what do you call your
own act? How long are we going to go on kidding each other? They've
shut me up here, but that doesn't mean they've stopped me from logical
thinking. My three old friends from the Project don't turn up in the
middle of a Friday morning just to calm my fevered brain with a card
game."

"What's wrong with poker?" demanded MacPherson.

"Poker? Nothing. I know--It must be the test. Total conversion of
matter to energy. Not just a minute percentage any more--_total_
conversion. They've finished the set, haven't they? They're ready to
test. They're going to disintegrate Waaku, aren't they? It must be
today. Then this is the day the world ends. Tell me, when is zero hour?"

Neill's cards had slipped from his fingers and he stooped to the floor,
fumbling for them. Avery was bending one corner of a card, creasing it,
smoothing it out, and creasing it again. Nobody was going to answer,
MacPherson realized. They were leaving it up to him.

He spoke sharply. "You're getting onto forbidden ground, Rothman. You
know we're not allowed to discuss the Project with you. We're allowed
to visit you only under the strictest promise not to speak of it at
all. You're certainly rational enough to understand what the therapists
have told you, that you'd get well easily enough if you'd stop
worrying. Forget about zero hour. Everything's going to be all right."

Rothman turned to look out the window. "Is it today?"

"How should we know? We're only innocent bystanders now, like you.
Remember, we all left the Project over six months ago, except Avery,
and last month they let him go."

Neill had rearranged his cards now and he looked at them instead of
Rothman as he spoke. "There's nothing to worry about. Your calculations
were wrong. The test is not going to get out of control--if and when
they make it. But they don't tell us things any more."

"Since they fired you," said Rothman.

"That's right, since they fired us," Neill said. The creased corner of
a card suddenly broke off in his fingers.

"If you didn't believe in my calculations, why did you back me up? I
didn't ask you to. If you didn't believe in the danger, why didn't you
stay out of the argument and keep your jobs? It wasn't your fight. You
could have kept out of it--or attacked me, like Avery."

"All we did was insist that even if you had made a mistake in your
calculations, that didn't necessarily prove you were crazy," said
Neill. "We didn't know whether you were right or not. We couldn't argue
about the math. Avery tore that to pieces and the boys at Columbia and
Harvard backed him up. MacPherson and I aren't competent to check your
math. To us, you didn't seem any crazier than the people who sent you
here. But after you'd scared them silly, they had to do something to
stop your scaring other people."

       *       *       *       *       *

He turned to pick up his cards again, but stopped at the sight of
Avery. Avery was standing and crumpling a card spasmodically, his lips
were moving without sound, and he was breathing rapidly.

"Look here," said MacPherson. "You'd better change the subject. If
little Joe passes by the door and hears us talking about the Project,
he'll have our visiting privileges revoked before you can say nuclear
fission, and they'll stay revoked forever."

"How long is forever?" asked Rothman.

Avery threw down his cards and walked to the window. Through the bars,
there was nothing to be seen but the expanse of sand, glinting in the
morning sun, and a cactus plant casting a stubby shadow. He whirled to
face the others.

"Look, MacPherson," he burst out. "I'm fed up with this game. Snookums
Rothman mustn't think about the Project any more, so we mustn't say the
naughty word. But we were all in it together at the beginning and there
was a while when we were all every bit as scared as he was. Why not
tell him we came this morning in case--just in case--he'd heard about
the test and was worrying? What's the harm in telling him what the
whole university knows? That zero hour is today, this morning, now!"

"Shut up, you fool!" said MacPherson.

But Rothman glanced at his cards again, then looked up. "When does it
begin? What time is it now?"

"Don't answer!" shouted MacPherson. "Are you trying to knock him off
balance again?"

"I will answer!" said Avery. "I'm going to tell him. He scared us silly
with his calculations; now let us scare him with some cold facts. It'll
do him good. Maybe when the test is over, if he finds--I mean _when_ he
finds--he was wrong, he'll be cured."

"Yes, and maybe he'll really be crazy."

Grabbing Avery fiercely by the arm, MacPherson tried to drag him to the
door, but Avery broke away.

"Listen, Rothman!" Avery's breath was coming quick and shallow. "Today
is the day! Zero hour is eleven o'clock this morning!"

       *       *       *       *       *

MacPherson sagged. No one spoke or moved as they all watched Rothman.

At last Rothman sighed, once. "What time is it now?"

From the door came a scratching sound. MacPherson turned to see Joe,
grinning at them through the steel lattice.

"How's things?" Joe wanted to know. "Thought I heard a commotion in
here. Doc Rothman's not acting up, I hope?"

"Everything's under control, Joe," MacPherson assured him. "Just having
a friendly game."

"Don't cheat while they're watching you," said Joe, and his face
disappeared.

"Well, the murder's out," said MacPherson.

"No use kidding you any longer," Neill said, fanning his cards.
"Eleven o'clock this morning. Six o'clock tomorrow morning, Waaku time.
But it's just another test. Nothing's going to happen."

Avery took off his glasses and began to polish the lenses. "Any idea
of a possible chain reaction is ridiculous. As a matter of fact, I
recently spent a full week checking the math again myself, so I know.
But we knew how you felt about it, Rothman, and we didn't want you to
be worrying here all alone, in case you'd found out. That's why we
came."

Rothman was looking out the window. He did not answer. Slowly
MacPherson went back to his chair and picked up his cards. "And now how
about playing some poker? Rothman, you opened for a blue. What about
you, Neill?"

"I'm staying," said Neill, shoving in a chip. "Always was a gambler.
I'm going to stay till the cows come home."

"What time is it?" Rothman asked. "I haven't got a wristwatch. They
think I might break the crystal and cut my throat."

MacPherson slammed down his cards and jerked his watch from his pocket.
"What does it matter what time it is? Why couldn't they give you a
watch with a plastic crystal? If you have to know, it's eleven-forty."

"And thirteen seconds," added Neill.

"Then it's already started," said Rothman.

       *       *       *       *       *

He leaned his head against the back of his chair and closed his eyes.
"It's on its way now. There's somewhat more than a third of the
Earth between us and Waaku--the place where Waaku was, I mean. The
disintegration wave is moving slowly. The seismic wave of an earthquake
would get here in about fifty minutes, more or less. But the shock wave
from Waaku, traveling somewhere around five thousand miles an hour,
will need about an hour and seventeen minutes, plus or minus a minute
or so. That means it will reach us in about thirty-seven minutes from
now, and the disintegration wave is following close behind. Well, nice
to have known you, fellows. Anyone want to check my math?"

He waved toward the desk behind him, piled high with manuscript and a
sprawling heap of books on which rested a slide-rule.

"Calm down," said MacPherson. "Nothing is going to happen. Damn you,
Avery! Are you proud of what you accomplished?"

Avery glared. "It'll do him good! He's got to learn to face reality,
like the rest of us. In a little more than half an hour, the test will
be finished. The world will still be here. Rothman will have to admit
his equations were wrong--and then he'll be cured."

Rothman leaned forward. "Or contrariwise, Rothman will _not_ have to
admit he was wrong and Rothman will _not_ be cured! If I made a mistake
in my math, why couldn't anybody put his finger on it? I'm not so crazy
that I wouldn't be able to see an error in calculus when it was pointed
out to me. If you're sure my calculations are wrong, why do you look so
frightened?"

"Do we have to go over all that again?" said MacPherson. "The boys
at Columbia told you where the mistake was. It's where you inverted
that twelve-by-twelve matrix. Didn't you bother to check the inverted
matrix?"

"The same old tale." Rothman picked up his cards. "No mathematician
will ever admit that another mathematician could invent a method beyond
his comprehension. Still harping on an error in my inverted matrix.
What time is it now?"

"There's no doubt that your calculations are wrong," said Neill, "but
I still don't see why we have to insist on proving it the hard way.
With bombs, why do we need to fool around with the total disintegration
of matter? Sure, I know the new model releases a googol times the
energy you get out of uranium fission, but who cares? There's plenty of
uranium for our needs."

"The trouble with uranium is that it doesn't make a big enough bang,"
said MacPherson. "People aren't impressed by it any more. The same
goes for plutonium, even for lithium, at least for any size bomb we
can make. The idea is to show the world something so convincing that
they'll never even think of a war again. When they see every island in
the Waaku chain wiped off the map, they'll get the point."

       *       *       *       *       *

Avery creased another card and cleared his throat. "_Did_ you check the
inverted twelve-by-twelve, Rothman?"

"I suppose you think I forgot to. Have _you_ checked it?"

"Yes, I have. I may not know much math, but I did check it."

"Even after the Columbia boys said it was nonsense? Well, does it come
out right?"

"No, it doesn't! You multiply the inverted matrix by the original and
you not only don't get zeros for all elements outside the diagonal,
you get a haphazard assortment of ones and twos. Worse still, every
element in the diagonal comes out equal to zero. The product of the two
matrices is about as different from the identity matrix as anything
could be. You're one of our most brilliant mathematicians--how could
you manage to make so many mistakes in one set of calculations?"

"Did I tell you that was an inverted matrix? Maybe, for this problem,
you need something a little more advanced than algebra. Anyhow, if my
math is all wrong, why did your first report okay it?"

"What do you mean, my first report?"

"The one you sent to Prexy. The one you later called in and burned.
Except Prexy showed it to me and I photostated it. Here." Rothman
reached into the pile of papers on his desk and drew out a little
envelope. It contained photographic prints. He held one before Avery's
glasses. "Does that look familiar?"

Avery drew his hand across his forehead, but did not reply.

"Is that true, Avery?" asked MacPherson. "Did you make a report okaying
Rothman's calculations and then withdraw it?"

"Well, what if I did? The report didn't seem to make me much more
popular than Rothman was. What if some very influential people in
Government explained to Prexy, and he explained to me, just how
unpopular that first report might make me? Or suppose they didn't.
Maybe I simply didn't find the mistakes in the math until later." Avery
kept looking at his cards as he spoke.

"Oh, great," said MacPherson. "Rothman gets put away here, Neill and
I lose our jobs, and there's hell to pay in Washington, all because
Avery says Rothman's math is full of holes. Now it turns out he wasn't
sure and maybe was pressured into it. Grand. Between a screwball and a
skunk, I'll choose the screwball. Maybe if Avery had stuck to his guns,
there wouldn't have been any test."

       *       *       *       *       *

"It doesn't matter," said Rothman. "Avery was probably warned to mend
his ways. I was. Or maybe he couldn't face the truth. I'm sure he's
been much happier, the last few months, believing I'm crazy. Anyway,
I don't blame him any more. Maybe my math will soon speak for itself.
For your benefit--" he turned to Avery--"I may point out that the
errors you said you found affect only the _velocity_ of the wave of
disintegration. So what if that isn't quite right? The proof that the
reaction will be self-sustaining is independent of that."

Avery was white with rage. "The proof, as you called it, that the
reaction will be self-sustaining and will consume the entire substance
of the Earth doesn't make sense, either. You used D as an operator
where it should have been a constant. That's what finally made them
certain that you were insane."

There was a rap at the door and Joe poked his head in. "Lunch,
Professors! Twelve o'clock, high noon, like they say. How about some
turkey sandwiches?"

MacPherson began to sweat; the thought of food made him feel sick.

Was it possible, he wondered, that in spite of everything, he was not
quite sure? He looked at Neill and Avery, but they had turned their
heads away.

"We won't bother with lunch, Joe," said Rothman.

"Must be a pretty good game if you won't even knock off to eat," said
Joe. "Well, will you at least mark your menu for tomorrow?"

"For tomorrow? Tomorrow isn't going to come, you know."

"Nuts," muttered Joe as he closed and locked the door. "Pure nuts."

Avery cleared his throat, and his voice was thin. "Look here, Rothman!
If the Universe were composed of matter as unstable as you claim,
it would have ceased to exist long ago. Somewhere, somehow, in the
infinity of chance events since the creation of the Earth, something
would have occurred to start the self-sustaining chain reaction, and
all matter would have been annihilated."

"Are you trying to prove something to yourself?" asked Rothman. "Surely
you don't equate infinity with a mere four billion years. That's
a finite time--long enough for the more dangerous radioactives to
disappear completely, of course, but not long enough for all possible
chance events to have taken place. Anyway, I never have asserted that
the reaction would reach from Earth to the other planets, or even to
the Moon. The Universe, including the Solar System, will still go on.
But our old Earth is going up like a pile of magnesium powder mixed
with potassium chlorate when you drop a lighted match on it."

       *       *       *       *       *

Avery wiped his forehead. "I don't know why I keep arguing with
a lunatic. But you know yourself that the value you give for the
integration constant in those equations is a pure guess, only you
spend ten pages of doubletalk trying to hide that fact. If the constant
is the one you give, why, sure, then you get a chain reaction. But
you made it up! Who ever heard of a constant of that magnitude in the
solution of an ordinary differential equation?"

"That's one criticism of my work the Harvard and Columbia boys never
mentioned."

"Okay, then I mention it. You're crazy!"

"Are you sure?"

"Positive!"

"Then why can't you forget the approach of zero hour? I'll tell you
why and you aren't even making a good show of hiding it. You know
that, compared to mine, your knowledge of mathematics is about on a
level with that of a college sophomore. Deep down, you know that my
calculations were correct. You are convinced--_convinced_--that the
bombing of Waaku has already started a chain reaction. And that about
seventeen minutes past twelve, around eight minutes from now, the shock
wave will reach us, and then the wave of disintegration. Look out of
the window! See that cactus in the sand, with its little yellow flower?
It will be annihilated. All that desert will go, too--every pebble,
every grain of sand. Everything you see, and you yourself, will be
disintegrated, transformed into energy!"

Suddenly he relaxed into a grin and softened his voice. "I thought we
were playing poker. We're waiting for you to bet. Why don't you at
least look at your cards?"

Avery opened his mouth, then closed it, and picked up his hand,
riffling the five cards.

"I'm staying," he said. "Here's your blue and I raise you a blue."

Slowly the others picked up their hands and stared at the cards.
MacPherson scarcely looked at his as he spoke.

"I'm staying." He picked up the deck. "Cards, gentlemen?"

Rothman shook his head. "I'll play these."

Neill took two. "I like to hold a kicker," he explained.

Avery and MacPherson drew three.

"I opened," said Rothman, "and I'll bet five blue chips."

"See you and raise you a blue," Neill said.

"I'll string along," said Avery.

MacPherson threw his hand in. "I'll let you guys fight it out."

       *       *       *       *       *

They all looked at Rothman, who was studying his cards.

"I'll see you," he began, and paused. Then he shoved all of his chips
into the pot. "I'll see you and raise you a hundred blue chips."

"Damn it Rothman!" MacPherson protested. "I know we agreed on no
limit, but if you go on playing like this, you'll lose more than you
can afford."

"I've already lost everything," said Rothman, "and so have you. Don't
you know what time it is? In a few minutes, none of you will be around
to try to collect. What time is it now?"

Avery reached for his watch, then stopped.

Rothman turned his head. "What's that?"

Nobody moved.

A noise like the roar of a swift freight train rushed into the
room, rattling the windows. The walls shook, the floor trembled, the
slide-rule slid off the pile of books and clattered to the floor.

They jumped to their feet and Avery ran to the window, clutching at the
bars.

"Not yet," said Rothman calmly. "The cactus plant will still be there,
casting its little shadow. You might as well sit down and finish the
game. That was only the shock wave. Have you forgotten that it is
transmitted through the Earth faster than the wave of disintegration?
We still have a few minutes left. Isn't anybody going to see my bet?"

Avery lurched to the desk, grabbed a remnant of torn paper and
scribbled on it

"I'll see you," he yelled, "and raise you a hundred and twenty-five
billion blues!"

MacPherson walked to the window. "Look at the sky. This is it."

They all jammed against his back, trying to see the horizon, waiting.
Avery dropped the scrap of paper and covered his eyes.

"What is there to see?" Neill whispered.

"I thought--there was a flash...." MacPherson's voice trailed off, and
he rubbed his eyes.

"But I didn't see anything," said Neill. "There's nothing to see."

       *       *       *       *       *

A minute went by. The desert remained calm, the blue sky was unmarked
by even a cloud, the air was still.

A second minute went by.

Neill drew out his watch, looked wonderingly at the steady march of
the second hand. Then he turned and stumbled into the lavatory. They
could hear his dry heaves.

Rothman's eyes wavered from MacPherson to Avery, and back to
MacPherson, and he sighed.

"Looks as if I was wrong, gentlemen," he said. "Maybe I am crazy, after
all. I wonder if that integration constant could have been wrong." He
reached down to the floor to pick up the fallen slide-rule, sat down
and drew a pad of paper toward him.

MacPherson leaned against the window, too weak to move. He saw Avery
take his hands away from his eyes. He could hear the chattering of
Avery's teeth, could hear them click as he clamped them together,
trying to control his lips. It seemed a long time before Avery managed
to speak.

"_You!_" cried Avery. He lunged forward, grabbed Rothman by the
shoulder and jerked him to his feet. "This--will teach you--not to
make--mistakes--"

He smashed his fist into Rothman's face.

Still MacPherson could not move, could not even shout. He could only
listen to Avery.

"And this will teach you--not to set up matrices--that don't
multiply--that burn up--the world--"

Again Avery struck and knocked Rothman to the floor.

Breaking through his paralysis, MacPherson clutched Avery by the
shoulder, but Avery kicked at the man on the floor, again and again.

"Avery!" shouted MacPherson. "Snap out of it, man! It's all over! The
test is finished. We're still here. Rothman was wrong, just as we
always knew he was!"

But Avery was on his knees, pounding Rothman with both fists, sobbing
out meaningless words, oblivious to the shouts outside and to
MacPherson's tugging.

The door burst open and Joe rushed in, followed by two other attendants.

"What goes on?" After a glance at Avery's contorted face, Joe grabbed
for his legs. "Send for the doc, boys. We're going to need help."

       *       *       *       *       *

One of the men ran down the corridor while Joe and the others succeeded
in pulling Avery away from Rothman, who struggled to his feet. A doctor
came in with a loaded hypodermic. He gave Avery an injection in the arm.

"Go easy there," said MacPherson. "He'll be all right in a few minutes.
He's had a shock, that's all."

"Shock," Avery mumbled.

MacPherson gripped Avery's arm. "Try to relax, man. It's finished. We
never believed in it, of course. But I'll admit it's a relief, even to
me, to be _sure_ there was no danger of a chain reaction at all."

Suddenly he felt cold.

There was no understanding in Avery's eyes. He slumped to the floor.

"Do you think he'll be all right when he comes out from under the
drug?" asked MacPherson.

"I can't say," said the doctor. "I only saw him a few minutes, when
you came here this morning. I thought at the time he was pretty
disturbed. Much more than Rothman here. Next week, I think, we're going
to send Rothman home."

Rothman wiped the blood off his chin and grinned weakly. "You don't
mean that, Doc. I used the wrong integration constant in a little
calculation. I must be crazy."