Gravity: A Novel of Medical Suspense

by Tess Gerritsen

  Profitt said, “I’ll authorize Dr. Roman to tell you everything. He’ll be expecting you at White Sands.” The phone went dead.

  Jack hung up and looked at Blankenship. “How long have you known?”

  Blankenship’s silence only fueled Jack’s anger. He took a threatening step forward, and Blankenship backed up against the kitchen wall. “How long have you known?”

  “Only—only a few days. I was sworn to secrecy!”

  “Those were our people dying up there!”

  “I had no choice! This has got everyone terrified! The White House. Defense.” Blankenship took a deep breath and looked Jack straight in the eye. “You’ll understand what I’m talking about. When you get to White Sands.”

  August 20

  With one end gripped in her teeth, Emma yanked the tourniquet tight, and the veins of her left arm plumped up like blue worms beneath the pale skin. She gave her antecubital vein a quick swipe of alcohol and winced at the prick of the needle. Like a junkie desperate for a fix, she injected the entire contents of the syringe, loosening the tourniquet halfway through. When she was finished, she closed her eyes and allowed herself to drift as she imagined the HCG molecules, like tiny stars of hope, coursing up her veins, swirling into her heart and lungs. Streaming out into arteries and capillaries. She imagined she could already feel its effect, the headache melting away, the hot flames of her fever smothered to a dying glow. Three doses left, she thought. Three more days.

  She imagined herself drifting out of her own body, and she saw herself, as though from a distance, curled up like a mottled fetus in a coffin. A bubble of mucus spilling out of her mouth, breaking into bright squirming threads like maggots.

  Abruptly she opened her eyes and realized that she had been sleeping. Dreaming. Her shirt was saturated with sweat. It was a good sign. It meant that her fever had eased off.

  She massaged her temples, trying to force out the images from her dream, but she could not; reality and nightmares had merged into one.

  She stripped off the sweat-soaked shirt and put on a clean one from Diana’s locker. Despite the bad dreams, that brief nap had refreshed her, and she was alert again, ready to search for new solutions. She floated into the U.S. lab and pulled up all the Chimera files on the computer. It was an extraterrestrial organism, Todd Cutler had informed her, and everything NASA now knew about the life-form had been transmitted to her onboard computers. She reviewed the files, hoping to find some new inspiration, some fresh approach that no one else had thought of. Everything she read was dismally familiar.

  She opened the genome file. A nucleotide sequence spilled across the monitor in an unending stream of A s, C s, T s, and G s. Here was Chimera’s genetic code—parts of it, anyway. The parts USAMRIID had chosen to share with NASA. She stared, hypnotized, as the lines of code marched down the screen. This was the essence of the alien life-form now growing inside her. It was the key to the enemy. If only she knew how to use it.

  The key.

  She suddenly thought of what Jack had said earlier, about hormones. In order for a hormone to work, it has to bind to a specific receptor on the target cell. It’s like a key in search of just the right lock in which to fit.

  Why would a mammalian hormone like HCG suppress the reproduction of an alien life-form? she wondered. Why would an extraterrestrial organism, so foreign to anything on earth, possess properly fitting locks to our keys?

  On the computer, the nucleotide sequence had finished scrolling to the end. She stared at the blinking cursor and thought of the earth-born species whose DNA had been raided by Chimera. By acquiring those new genes, this alien life-form had become part human. Part mouse. Part amphibian.

  She got on the comm with Houston. “I need to speak to somebody in Life Sciences,” she said.

  “Anyone in particular?” asked Capcom.

  “An amphibian expert.”

  “Stand by, Watson.”

  Ten minutes later, a Dr. Wang from NASA Life Sciences came on the loop. “You had a question about amphibians?” he asked.

  “Yes, about Rana pipiens, the northern leopard frog.”

  “What can I tell you about it?”

  “What happens if you expose the leopard frog to human hormones?”

  “Any hormone in particular?”

  “Estrogen, for instance. Or HCG.”

  Dr. Wang answered without hesitation. “Amphibians in general are adversely affected by environmental estrogens. It’s been studied quite a bit, actually. A number of experts think the worldwide decline in frog populations is due to estrogenlike substances polluting streams and ponds.”

  “What estrogenlike substances?”

  “Certain pesticides, for instance, can mimic estrogens. They disrupt the frogs’ endocrine systems, making it impossible for them to reproduce or thrive.”

  “So it doesn’t actually kill them.”

  “No, it just disrupts reproduction.”

  “Are frogs in particular sensitive to this?”

  “Oh, yes. Far more than mammals. Plus, frogs have permeable skin, so they’re susceptible to toxins in general. That’s sort of their, well, Achilles’ heel.”

  Achilles’ heel. She fell silent for a moment, thinking about that.

  “Dr. Watson?” said Wang. “You have any other questions?”

  “Yes. Is there any disease or toxin that would kill a frog, but not harm a mammal?”

  “That’s an interesting question. When it comes to toxins, it would depend on the dose. You give a little arsenic to a frog, you’d kill it. But arsenic would kill a man as well, if he’s given a larger dose. Then again, there are microbial diseases, certain bacteria and viruses, that only kill frogs. I’m not a physician, so I’m not absolutely certain they’re harmless to humans, but—”

  “Viruses?” she cut in. “Which ones?”

  “Well, Ranaviruses, for instance.”

  “I’ve never heard of those.”

  “Only amphibian experts are familiar with them. They’re DNA viruses. Part of the Iridovirus family. We think they’re the cause of tadpole edema syndrome. The tadpoles swell up and hemorrhage.”

  “And that’s fatal to them?”

  “Very much so.”

  “Does this virus kill people as well?”

  “I don’t know. I don’t think anyone does. I do know Ranaviruses have killed off whole populations of frogs around the world.”

  The Achilles’ heel, she thought. I’ve found it.

  By adding the leopard frog’s DNA to its own genome, Chimera had become part amphibian. It had also acquired an amphibian’s vulnerabilities.

  She said, “Is there any way to obtain live samples of one of these Ranaviruses? To test against Chimera?”

  There was a long silence. “I get it,” said Dr. Wang. “No one’s tried that yet. No one’s even considered—”

  “Can you get the virus?” she cut in.

  “Yes. I know two amphibian research labs in California who are working with live Ranaviruses.”

  “Then do it. And get hold of Jack McCallum. He needs to know about this.”

  “He and Gordon Obie just left for White Sands. I’ll reach them there.”

  Tumbleweeds skittered across the road, swept along in a stinging cloud of sand. The men drove past the guardhouse, past the electrified fence, and into the barren Army compound. Jack and Gordon stepped out of the vehicle and squinted up at the sky. The sun was a dusky orange, obscured by windblown dust. The color of sunset, not high noon. They had managed to catch only a few hours of sleep before they’d taken off from Ellington, and it hurt Jack’s eyes just to see the light of day.

  “This way, gentlemen,” the driver said.

  They followed the soldier into the building.

  It was a different reception from the last time Jack had visited. This time the Army escort was polite and respectful. This time Dr. Isaac Roman was waiting at the front desk, although he did not look particularly happy about their arrival.

 
; “Only you are allowed to come with me, Dr. McCallum,” he said. “Mr. Obie will have to wait here. That was the agreement.”

  “I made no such agreement,” said Jack.

  “Mr. Profitt did, on your behalf. He’s the only reason you’re being allowed in this building. I haven’t a great deal of time, so let’s get this over with.” He turned and walked to the elevators.

  “Now, there’s your standard Army-issue asshole,” said Gordon. “Go on. I’ll wait here.”

  Jack followed Roman into the elevator.

  “First stop is subbasement level two,” said Roman, “where we house our animal trials.” The elevator door opened, and they confronted a wall of glass. It was a viewing window.

  Jack approached the window and stared at the laboratory beyond. Inside were a dozen workers wearing biocontamination suits. Cages held spider monkeys and dogs. Right beside the window were glass-enclosed rat cages. Roman pointed to the rats. “You’ll notice each cage is labeled with the date and time they were infected. I can think of no better way to illustrate Chimera’s lethal nature.”

  In the Day 1 cage, the six rats appeared healthy, vigorously spinning their exercise wheels.

  In the cage labeled “Day 2,” the first signs of illness appeared. Two of the six rats were shivering, their eyes a bright bloodred. The other four were huddled in a lethargic heap.

  “The first two days,” said Dr. Roman, “is Chimera’s reproductive phase. You understand, this is completely opposite to what we see on earth. Usually a life-form must reach maturity before it begins to reproduce. Chimera reproduces first, and then begins to mature. It divides at a rapid rate, producing up to a hundred copies of itself by forty-eight hours. They start out microscopic in size—not visible to the naked eye. Small enough so that you could breathe them in, or absorb them through your mucous membranes, and not even know you’ve been exposed.”

  “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 call them. Egg sacs, I suppose. Because they contain a larval life-form 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, the caterpillar is alive. Incubating a foreign life-form that’s eating it from the inside, until the larvae finally burst out of their dying host.” Roman looked at the dead rats. “These larvae, too, multiply and develop inside a living victim. And that’s what finally kills the host. All those larvae, packing into the cranium. Nibbling away at 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 life-form 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. The genome has become more complex. The life-form 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 Galápagos Rift for more of these things. This organism, in the wrong hands . . .” His voice 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 all 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 life-form 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. First 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. If only I could buy more time.

  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 life-for
m 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 softly.

  “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 in was completely destroyed.”

  “And USAMRIID’s raid on her lab? You weren’t there to investigate, were you? You were there to see that all her files were destroyed.”