Another crack. Another spattering of blood and bone.

He should have been dead. Why was he still seizing?

But even decapitated chickens continue to twitch and thrash, and Helsinger’s death throes were not yet over. His head lifted the floor, his spine curling forward like a spring winding up to unbearable tension just before it snaps. His neck lashed backward.

There was a crack, and the skull split open like an egg. Shards of bone flew everywhere. A lump of gray matter splashed the window.

Roman gasped and stumbled backward, nausea rising in his throat. He dropped his head, fighting to stay in control. He struggled against the darkness that threatened to envelop his vision.

Sweating, shaking, he managed to lift his head. To look, once again, through the window.

Nathan Helsinger at last lay still. What was left of his head rested in a lake of blood. There was so much blood that for a moment Roman could not focus on anything else but that spreading pool of scarlet. Then his gaze settled on the dead man’s face. On a blue-green mass that clung, quivering, to his forehead. Cysts.

Chimera.

August 14

“Nicolai? Nicolai, please respond!”

“My ear—It is in my ear—”

“Pain? Does your ear hurt? Look at me!”

“It’s going deeper! Get it out! Get it now!”

White House Security Council science adviser Jared Profitt pressed the OFF button on the cassette recorder and looked at the men and women seated around the table. All of them wore expressions of horror. “What happened to Nicolai Rudenko was more than just a decompressive accident,” he said. “That’s why we took the action we did. That’s why I urge you all to stay the course. There’s too much at stake. Until we learn more about this organism—how it reproduces, how it infects—we can’t let those astronauts come home.”

The response was stunned silence. Even NASA administrator Leroy Cornell, who had led off the meeting with an outraged about the takeover of his agency, sat utterly speechless.

It was the president who asked the first question. “What do we know about this organism?”

“Dr. Isaac Roman from USAMRIID can answer that better than I can,” said Profitt, and he nodded to Roman, who was not seated the table, but on the periphery, where he’d been largely by everyone in the room. Now he stood so that he could be seen, tall and graying man with the look of exhaustion in his eyes.

“I’m afraid the news is not good,” he said. “We’ve injected Chimera into a number of different mammalian species including dogs and spider monkeys. Within ninety-six hours, all were dead. mortality rate of one hundred percent.”

“And there’s no treatment? Nothing has worked?” asked the secretary of defense.

“Nothing. Which is frightening enough. But there’s worse news.” The room went very still as fear rippled across faces. How could this get any worse?

“We have repeated the DNA analysis of the most recent generation of eggs, collected from the dead monkeys. Chimera has acquired yet a new cluster of genes, specific to Ateles geoffroyi, spider monkey.

The president blanched. He looked at Profitt. “Does this mean what I think it means?”

“It’s devastating,” said Profitt. “Every time this life-form goes through a new host, every time it produces a new generation, it seems to acquire new DNA. It has the ability to stay several steps ahead of us by picking up new genes, new capabilities it’s never had before.”

“How the hell can it do this?” asked General Moray of the Joint Chiefs of Staff. “An organism that picks up new genes? That keeps remaking itself? It sounds impossible.”

Roman said, “It’s not impossible, sir. In fact, a similar occurs in nature. Bacteria often share genes with each other, trading them back and forth by using viruses as couriers. That’s they develop antibiotic resistance so quickly. They spread around the genes for resistance, adding new DNA to their chromosomes. Like everything else in nature, they’ll use every weapon they have to survive. To perpetuate their species. That’s what this is doing.” He moved to the head of the table, where a blowup of an electron micrograph was displayed. “You can see here, in this photograph of the cell, what looks like tiny granules. They’re clumps of helper virus.

Couriers that travel into the host cell, its DNA, and bring back bits and pieces of genetic material to Chimera. Adding new genes, new weapons to its arsenal.” Roman looked at the president. “This organism came equipped to survive any environmental conditions. All it needs to do is raid the local fauna’s DNA.”

The president looked ill. “So it’s still changing. Still evolving.” There were murmurs of dismay around the table. Frightened glances, creaking chairs.

“What about that doctor who got infected?” asked a woman from the Pentagon. “The one USAMRIID had in Level Four isolation? Is he still alive?”

Roman paused, a look of pain in his eyes. “Dr. Helsinger died late last night. I witnessed the terminal event and it was a horrible death. He began to convulse so violently we didn’t dare control him for fear someone’s space suit would be torn and someone else exposed. These were seizures unlike any I’ve ever seen. It was though every single neuron in his brain fired at once in a electrical storm. He broke the bed rail. Snapped it cleanly off the frame. Rolled off the mattress and began to—to batter his head on the floor. So hard, we could…” He swallowed.

“We could see the skull crack. By then there was blood flying everywhere. He was smashing his head against the floor, almost as if he was trying to break it open. To release the pressure building up inside. The trauma only made it worse, because he began to bleed into his brain. At the end, the intracranial pressure was so great, it pushed his eyes out of their sockets. Like a cartoon character. Like an animal you see squashed on the road.” He took a deep breath. “That, he said quietly, “was the terminal event.”

“Now you understand the possible epidemic we face,” said Profitt. “This is why we can’t afford to be weak or careless. Or sentimental.” There was another long silence. Every one looked at the president.

They were all waiting for—hoping for—an unequivocal decision.

Instead, he swiveled his chair toward the window and stared outside. “I wanted to be an astronaut, once,” he said sadly.

Didn’t we all? thought Profitt. Which child in this country has not dreamed of riding a rocket into space?

“I was there when they launched John Glenn on the shuttle,” the president said. “And I cried. Just like everyone else. Goddamn it, but I cried like a baby. Because I was proud of him. And proud of this country. And proud of just being part of the human race…”

He paused. Took a deep breath and wiped his hand across his eyes.

“How the hell do I condemn those people to death?” Profitt and Roman exchanged unhappy glances.

“We have no choice, sir,” said Profitt. “It’s five lives versus the lives of God knows how many people here on earth.”

“They’re heroes. Honest-to-God heroes. And we’re going to leave them up there to die.”

“The chances are, Mr. President, we wouldn’t be able to save them anyway,” said Roman. “All of them are probably infected. Or they soon will be.”

“Then some of them may not be infected?”

“We don’t know. We do know Rudenko definitely is. We believe he was exposed while in his EVA suit. If you’ll recall, Astronaut Hirai was found seizing in the EVA equipment lock ten days ago. That would explain how the suit got contaminated.”

“Why aren’t the others sick yet? Why only Rudenko?”

“Our studies indicate this organism needs incubation time before it reaches the infectious stage. We think it’s most around the time the host dies, or afterwards, when it’s released from the corpse. But we’re not certain. We can’t afford to be wrong. We have to assume they’re all carriers.”