As he fell he pulled hard. Then the numbing darkness settled over him completely. He did not feel the smashing impact of the floor as it came up at him.

Out into space the ship rose, automatic relays pumping frantically. But inside no one moved.

Eller opened his eyes. His head throbbed with a deep, aching beat. He struggled to his feet, holding onto the hull railing. Harrison Blake was coming to life also, groaning and trying to rise. His dark face had turned sickly yellow, his eyes were blood-shot, his lips foam-flecked. He stared at Cris Eller, rubbing his forehead shakily.

“Snap out of it,” Eller said, helping him up. Blake sat down in the control chair.

“Thanks.” He shook his head. “What-what happened?”

“I don’t know. I’m going to the lab and see if Silv is all right.”

“Want me to come?” Blake murmured.

“No. Sit still. Don’t strain your heart. Do you understand? Move as little as possible.”

Blake nodded. Eller walked unsteadily across the control room to the corridor. He entered the drop lift and descended. A moment later he stepped out into the lab.

Silvia was slumped forward at one of the work tables, stiff and unmoving.

“Silv!” Eller ran toward her and caught hold of her, shaking her. Her flesh was hard and cold. “Silv!”

She moved a little.

“Wake up!” Eller got a stimulant tube from the supply cabinet. He broke the tube, holding it by her face. Silvia moaned. He shook her again.

“Cris?” Silvia said faintly. “Is it you? What—what happened? Is everything all right?” She lifted her head, blinking uncertainly. “I was talking to you on the vidscreen. I came over to the table, then all of a sudden—”

“It’s all right.” Eller frowned, deep in thought, his hand on her shoulder. “What could it have been? Some kind of radiation blast from the asteroid?” He glanced at his wristwatch. “Good Lord!”

“What’s wrong?” Silvia sat up, brushing her hair back. “What is it, Cris?

“We’ve been unconscious two whole days,” Eller said slowly, staring at his watch. He put his hand to his chin. “Well, that explains this.” He rubbed at the stubble.

“But we’re all right now, aren’t we?” Silvia pointed at the hamsters in their cages against the wall. “Look—they’re up and running around again.”

“Come on.” Eller took her hand. “We’re going up above and have a conference, the three of us. We’re going over every dial and meter reading in the ship. I want to know what happened.”

Blake scowled. “I have to agree. I was wrong. We never should have landed.”

“Apparently the radiation came from the center of the asteroid.” Eller traced a line on the chart. “This reading shows a wave building up quickly and then dying down. A sort of pulse wave from the asteroid’s core, rhythmic.”

“If we hadn’t got into space we might have been hit by a second wave,” Silvia said.

“The instruments picked up a subsequent wave about fourteen hours later. Apparently the asteroid has a mineral deposit that pulses regularly, throwing out radiation at fixed intervals. Notice how short the wave lengths are. Very close to cosmic ray patterns.”

“But different enough to penetrate our screen.”

“Right. It hit us full force.” Eller leaned back in his seat. “That explains why there was no life on the asteroid. Bacteria landing would be withered by the first wave. Nothing would have a chance to get started.”

“Cris?” Silvia said.

“Yes?”

“Cris, do you think the radiation might have done anything to us? Are we out of danger? Or—”

“I’m not certain. Look at this.” Eller passed her a graph of lined foil, traced in red. “Notice that although our vascular systems have fully recovered, our neural responses are still not quite the same. There’s been alteration there.”

“In what way?”

“I don’t know. I’m not a neurologist. I can see distinct differences from the original tracings, the characteristic test patterns we traced a month or two ago, but what it means I have no way to tell.”

“Do you think it’s serious?”

“Only time will tell. Our systems were jolted by an intense wave of unclassified radiation for a straight ten hours. What permanent effects it has left, I can’t say. I feel all right at this moment. How do you feel?”

“Fine,” Silvia said. She looked out through the port scope at the dark emptiness of deep space, at the endless fragments of light arranged in tiny unmoving specks. “Anyhow, we’re finally heading Terra-side. I’ll be glad to get home. We should have them examine us right away.”

“At least our hearts survived without any obvious damage. No blood clots or cell destruction. That was what I was primarily worried about. Usually a dose of hard radiation of that general type will—”

“How soon will we reach the system?” Blake said.

“A week.”

Blake set his lips. “That’s a long time. I hope we’re still alive.”

“I’d advise against exercising too much,” Eller said. “We’ll take it easy the rest of the way and hope that whatever has been done to us can be undone back on Terra.”

“I guess we actually got off fairly easy.” Silvia said. She yawned. “Lord, I’m sleepy.” She got slowly to her feet, pushing her chair back. “I think I’ll turn in. Anyone object?”

“Go ahead,” Eller said. “Blake, how about some cards? I want to relax. Blackjack?”

“Sure,” Blake said. “Why not?” He slid a deck from his jacket pocket. “It’ll make the time pass. Cut for deal.”

“Fine.” Eller took the deck. He cut, showing a seven of clubs. Blake won the deck with a jack of hearts.

They played listlessly, neither of them much interested. Blake was sullen and uncommunicative, still angry because Eller had been proved so right. Eller himself was tired and uncomfortable. His head throbbed dully in spite of the opiates he had taken. He removed his helmet and rubbed his forehead.

“Play,” Blake murmured. Under them the jets rumbled, carrying them nearer and nearer Terra. In a week they would enter the system. They had not seen Terra in over a year. How would it look? Would it still be the same? The great green globe, with its vast oceans, all the tiny islands. Then down at New York Spaceport. San Francisco, for him. It would be nice, all right. The crowds of people, Terrans, good old frivolous, senseless Terrans, without a care in the world. Eller grinned up at Blake. His grin turned to a frown.

Blake’s head had drooped. His eyes were slowly closing. He was going to sleep.

“Wake up,” Eller said. “What’s the matter?”

Blake grunted, pulling himself up straight. He went on dealing the next hand. Again his head sank lower and lower.

“Sorry,” he murmured. He reached out to draw in his winnings. Eller fumbled in his pocket, getting out more credits. He looked up, starting to speak. But Blake had fallen completely asleep.

“I’ll be damned!” Eller got to his feet. “This is strange.” Blake’s chest rose and fell evenly. He snored a little, his heavy body relaxed. Eller turned down the light and walked toward the door. What was the matter with Blake? It was unlike him to pass out during a game of cards.

Eller went down the corridor toward his own quarters. He was tired and ready for sleep. He entered his washroom, unfastening his collar. He removed his jacket and turned on the hot water. It would be good to get into bed, to forget everything that had happened to them, the sudden exploding blast of radiation, the painful awakening, the gnawing fear. Eller began to wash his face. Lord, how his head buzzed. Mechanically, he splashed water on his arms.

It was not until he had almost finished washing that he noticed it. He stood for a long time, water running over his hands, staring silently down, unable to speak.

His fingernails were gone.

He looked up in the mirror, breathing quickly. Suddenly he grabbed at his hair. Handfuls of hair came out, great bunches of light brown hair. Hair and nails—