Tess Gerritsen: Gravity

"So they're infectious at this early stage in their life cycle?"

"They're infectious at any stage of their life cycle. They only have to be released into the air. Usually it happens around the time of the victim's death, or when the corpse bursts open several days post mortem. Once Chimera's infected you, once it's multiplied inside your body, each individual copy begins to grow. Begins to develop into ... " He paused. "We don't really know what to them. Egg sacs, I suppose. Because they contain a larval lifeform inside them." Jack's gaze moved on, to the Day 3 enclosure. All the mice were twitching, limbs thrashing as though repeatedly jolted by electric shocks.

"By the third day," said Roman, "the larvae are growing rapidly. Displacing the victim's brain matter by sheer mass effect. Wreaking havoc with the host's neurologic functions. And by day four … "

They looked at the fourth enclosure. All but one were dead.

The corpses had not been removed, they lay stiff-legged, mouths gaping open. There were still three cages to go, the process of decomposition had been allowed to continue.

By day five, the corpses were beginning to bloat.

On day six, the bellies had grown even larger, the skin stretched drum-taut. viscous fluid seeped from the open eyes and glistened on the nostrils.

And on day seven ... Jack halted beside the window, staring into the seventh enclosure.

Ruptured corpses littered the bottom like deflated balloons, the skin torn open to reveal a black stew of dissolved organs. And adhering to one rat's face was a gelatinous mass of opaque globes.

They were quivering.

"The egg sacs," said Roman. "By this stage, the corpse's body cavities are packed with them. They grow at an astonishing rate, feeding on host tissues. Digesting muscles and organs." He looked at Jack. "Are you familiar with the life cycle of parasitic wasps?

Jack shook his head.

"The adult wasp injects its eggs into a living caterpillar. The larvae grow, ingesting their host's hemolymph fluid. All this time, caterpillar is alive. Incubating a foreign lifeform that's eating from the inside, until the larvae finally burst out of their dying host." Roman looked at the dead rats. "These larvae, too, and develop inside a living victim. And that's what finally kills host. All those larvae, packing into the cranium. Nibbling away the surface of the gray matter. Damaging capillaries, causing intracranial bleeding. The pressure builds. Vessels in the eyes engorge, burst. The host experiences blinding headaches, confusion. He stumbles around as though drunk. In three or four days, he is dead. And still the lifeform continues to feed on the corpse. Raiding its DNA. Using that DNA to speed its own evolution."

"Into what?" Roman looked at Jack. "We don't know the end point. With every generation, Chimera acquires DNA from its host. The Chimera we're working with now is not the same one we started out with. Its genome has become more complex. The lifeform more advanced." More and more human, thought Jack.

"This is the reason for absolute secrecy," said Roman. "Any terrorist, any hostile country, could mine the Galapagos Rift for of these things. This organism, in the wrong hands ... " His trailed off.

"So nothing about this thing is manmade." Roman shook his head. "It was found by chance in the rift. Brought up to the surface by Gabriella. At first Dr. Koenig thought she'd discovered a new species of Archaeons. Instead, what she found was this." He looked at the wriggling mass of eggs. "A thousand years, they've been trapped in the remains of that asteroid. At a depth of nineteen thousand feet. That's what has kept it in check this time. The fact it came to rest in the deep sea, and not on land."

"Now I understand why you tested the hyperbaric chamber."

"All this time Chimera has existed benignly in the rift. We thought, if we reproduced those pressures, we could make it benign again."

"And can you?"

Roman shook his head. "Only temporarily. This lifeform has been permanently altered by exposure to microgravity. Somehow, when it was brought to ISS, its reproductive switch was turned on. It's as if it was preprogrammed to be lethal. But it needed the absence of gravity to start that program running again."

"How temporary is hyperbaric treatment?"

"Infected mice stay healthy as long as they're in the chamber. We've kept them alive ten days now. But as soon as we take any of them out, the disease continues its progression."

"What about Ranavirus?" Only an hour ago, Dr. Wang from NASA Life Sciences had briefed Jack by phone. At that very moment, a supply of the amphibian virus was winging its way by Air Force jet to Dr. Roman's lab. "Our scientists believe it could work."

"Theoretically. But it's too early to launch a rescue shuttle. We have to prove Ranavirus works, or you'd risk the lives of another shuttle crew. We need time to test the virus. Several weeks, at least." Emma doesn't have weeks, thought Jack. She has only three days' worth of HCG. In silence he gazed down at the cage of rat corpses. At the eggs, glistening in their nest of slime.

Time. A thought suddenly occurred to him. The memory of something Roman had just said.

"You said the hyperbaric chamber has kept mice alive for ten days so far."

"That's correct."

"But it was only ten days ago that Discovery crashed." Roman avoided his gaze.

"You planned the chamber tests right from the start. Which means you already knew what you were dealing with. Even before you performed the autopsies." Roman turned and started to walk back to the elevator. He gave a gasp of surprise when Jack caught him by the collar and spun him around.

"That wasn't a commercial payload," said Jack. "Was it?" Roman pushed away and stumbled backward, against the wall.

"Defense used SeaScience as a cover," said Jack. "You paid them to send up the experiment for you. To hide the fact that this lifeform is of military interest." Roman sidled toward the elevator. Toward escape.

Jack grabbed the man's lab coat and tightened his grip on the collar.

"This wasn't bioterrorism. This was your own fucking mistake!"

Roman's face had turned purple. "I can't -- can't breathe!" Jack released him, and Roman slid down the wall, his legs collapsing beneath him. For a moment he didn't speak, but sat slumped on the floor, struggling to catch his breath. When at last he did talk, all he could manage was a whisper.

"We had no way of knowing what it would do. How it would change without gravity ... "

"But you knew it was alien."

"Yes."

"And you knew it was a chimera. That it already had amphibian DNA.

"No. No, we didn't know that."

"Don't bullshit me."

"We don't know how the frog DNA got onto the genome! It must have happened in Dr. Koenig's lab. A mistake of some kind. She was the one who found the organism in the rift, the one who finally realized what it was. SeaScience knew we'd be interested. An extraterrestrial organism -- of course we were! Defense paid for their KC-135 experiments. We funded the payload space on ISS. It couldn't go up as a military payload. There'd be too many questions asked, too many review committees. NASA would wonder why the Army cared about harmless sea microbes. But no one questions the private sector. So it went up as a commercial payload, with SeaScience as sponsor. And Dr. Koenig as principal investigator.

"Where is Dr. Koenig?"

Slowly Roman rose to his feet. "She's dead."

That information took Jack by surprise. "How?" he asked.

"It was an accident."

"You think I believe that?"

"It's the truth." Jack studied the man for a moment and decided Roman was not lying.

"It happened over two weeks ago in Mexico," said Roman.

"Just after she resigned from SeaScience. The taxi she was riding was completely destroyed."