Bred to Kill (36 page)

A
virus . . . The word echoed over and over in Sharko's brain like a tape loop.

A virus from another age, as old as humanity, that had probably infected the Cro-Magnon in the cave and made him drunk with violence. What could it be related to? Had it also contaminated Grégory Carnot and Félix Lambert? Where did it come from? How had it spread?

The inspector and the Homicide squad leader arrived at their destination. On the way, they had spoken only a few words, each one sunk in his private torment. Sharko was thinking of Lucie. By then, she must have been at the edge of the unknown, powerless and fragile. How would she make it back out? What if something happened to her? If she were wounded or . . . how would he even hear about it?

In a locker room adjacent to the lab, the two men put on sterile coveralls.

“Are you sure it's not dangerous to go in there?” Sharko finally said. “That virus, I mean . . . It can't infect us, can it?”

“It isn't airborne and it can't spread by touch, if that's what you're worried about. And besides, it's a controlled environment.”

Sharko slipped on a pair of overshoes.

“What about the investigation? What's happening? Anything new?”

“You ready? Let's go in.”

After passing through an airlock, the two men entered the molecular biology lab. The room was filled with every variety of microscope, from electron to scanning tunneling, enormous machines set on antivibration platforms, hundreds of pipettes, stacks of petri dishes. At nearly 4 p.m., things were agitated in that universe of the infinitely small. People were running back and forth, conferring animatedly.

“Their orders are not to tell anyone about what they've found here,” Bellanger whispered. “With what's going on under their microscopes, they're all on edge and aware that they might be making the discovery of the century.”

Jean-Paul Lemoine rushed up to them in a state of high excitement. He firmly shook Sharko's hand.

“Give him the details,” said Bellanger, “so that he can grasp the full import of this.”

“Everything? Even the part about Félix Lambert? I thought you said . . .”

“Everything.”

The head of the laboratory rubbed his chin, probably wondering where to begin. He pulled Sharko over to a quieter area in the back of the room.

“Hmmm . . . It's not easy to explain. First thing, do you know what a retrovirus is?”

“Tell me.”

“AIDS is a good example. Basically, a retrovirus is a little wise guy with some scissors and paste, and using these he integrates his genome—his own sequence of A, T, C, and G's—into the DNA of the cells he's contaminated, and hides there. As such, he becomes invisible to the body's immune system, which then becomes powerless to fight it. Thanks to the cell mechanism, the virus's hidden genome is read and analyzed by our little internal engineer, who goes over every letter of the DNA. This little engineer, who doesn't realize he's got an intruder on his hands, does what he'd normally do with any sequence he reads: he makes a protein, which will serve to build human tissues. Except that in reality, this protein is a new virus let loose inside the organism, which will go infect another cell and start the process over again, and so on ad infinitum. This propagation occurs to the detriment of the other cells, like the decrease in lymphocytes in HIV, and therefore of the body's immune defenses. Broadly speaking, that's how a retrovirus works. Oh, one last thing: a retrovirus is called ‘endogenous' if it's transmitted from generation to generation. It hides in the embryo and can stay dormant for twenty or even thirty years.”

An embryo . . . Sharko recalled the tragic deliveries of Lambert's mother and Amanda Potier, the fatal hemorrhages. Could this be related to that? Bellanger brought them hot coffee. The biologist took a small sip, then continued:

“So, as I was saying. Until not so long ago, we thought that ninety-eight percent of the DNA molecule had no particular use. We called that part—and still call it—‘junk DNA.' All of our genetic heritage, the thirty thousand genes that make up our blue eyes, dark hair, or stocky build are distributed over only two percent of useful DNA. The rest is just . . . filler, waste.”

“Two percent? So in a way, you could . . . burn almost the entire encyclopedia of life without causing any genetic damage?”

“That's what we believed for a long time.”

Sharko imagined Daniel's vast library reduced to a single shelf.

“But the fact is, nature never creates anything useless. And we finally realized, when we decoded the genome, that an earthworm had almost as many genes as we do. And yet we're infinitely more complex. Which must mean that the so-called junk DNA contains a number of secrets. Today we know that certain portions of that junk DNA participate in the organism's functioning, interact with the genes we've identified. They're the keys to a whole multitude of locks, if you will, which could never be opened without them. Most of all, we've recently understood that more than eight percent of junk DNA was composed of genetic fossils. The fossils of thousands of retroviruses from past generations, which we call HERVs, for human endogenous retroviruses.”

Sharko sighed, a hand on his forehead.

“I had a miserable night last night—can you put that a bit more plainly?”

The biologist gave him a pinched smile.

“More plainly? All right, let's see. There are thousands of ‘aliens' in our genome, Inspector. They live among us, hidden in a dark corner of our DNA. A kind of ancient AIDS, prehistoric monstrosities, mummified microscopic serial killers, which infected our ancestors millions of years ago, then were transmitted from generation to generation and now lie dormant in the DNA of every person on this planet.”

This time Sharko got a clearer picture, and the horrible thought of it made him shiver. He imagined the DNA molecule as a kind of net dredging up everything that lay around, storing it all away without ever purging itself, just getting fatter and fatter.

“What keeps all those fossilized retroviruses from waking up? How come they aren't infecting us now?”

“It's more complicated than that. Every time, the process is the same: the infectious agent inserts itself into the cell's DNA, including the reproductive cells, then is transmitted through procreation like any other genetic heritage. Over time, the HERV undergoes several mutations—its A, T, C, and G's change—and it gradually loses its ability to be harmful. Like all those volcanoes that became extinct over geological time.”

“And why does the retrovirus mutate?”

“Because of evolution. If it's harmful to humans, if it contains more drawbacks than advantages, the evolution of the human race will do everything it can to eradicate it. So over thousands of years, the virus progressively finds itself unable to do what it was designed to do, in other words manufacture a complete viral envelope that lets it forge its destructive path from cell to cell. But that doesn't mean it's dead. Certain mutated retroviruses were
tamed
by evolution and now play a very advantageous role in certain physiological processes. For example, a mutated retrovirus from the HERV-W family participates actively in the formation of the placenta. Stéphane Terney was among those who claimed that if this particular retrovirus hadn't invaded living species a long time ago, mammals would never have existed. Females—including human females—would have given birth outside the body, most likely in eggs. The mutated retrovirus thus played a major part in the evolution of these species of animals.”

Sharko tried to pay attention. Certain words, like “placenta,”
“
virus,” “Terney,” kept ringing little warning bells in his mind.

“So Terney was knowledgeable about retroviruses?” he asked.

“As an immunologist and with regard to what I just explained, yes. I'll give you one more example of evolution taming a foreign body in humans: sickle-cell anemia. It's a hereditary illness fairly common among African populations, which hasn't been eliminated by evolution because it confers a greater resistance to malaria. The advantage gained from it—the antimalarial protection—is deemed to be greater than its disadvantages.”

Lemoine set down two sets of three printed sheets in front of the inspector. The one on the left was in Daniel's handwriting. Each sheet contained an infinite series of A, T, G, C.

“Let's cut to the chase. On the left you've got the mysterious retroviral sequence you gave us, and I hope you can tell us where you got it.”

“How do you know it's a retrovirus?”

“All retroviruses have the same signature, the same starter initiating the sequence. When you see a pistol, you can identify the make, right? Same for me with DNA.”

He pressed his finger onto one of the sheets on the right.

“These pages show the sequence of one of thousands of fossilized retroviruses found in the junk DNA of all of us—yours and mine. We know this retrovirus belongs to the HERV-W family. We find it somewhere in the first third of chromosome two. Until today, we had no idea what its function might have been in past millennia. All we knew was that this sequence had appeared only in the hominid branch, because we don't find it in the genome of any other animal, vegetable, or fungus.”

“A virus specific to humans . . .”

“So it seems. We know nothing about it. Its function, its virulence, its destructive power at the time. But the case you're working on is about to mark a turning point in genetics and molecular biology. I'd even say a turning point in human evolution.”

Sharko was stunned by such grandiose claims. He looked at the twin sets of papers, put the two top pages side by side. The sequence on the right was practically identical to the one on the left, apart from the occasional extraneous letter that the biologist had highlighted in Day-Glo blue. The difference occurred roughly once every hundred letters.

“Some of these anomalies, we're not sure which, rendered this retrovirus inert,” Lemoine explained. “It's now just a piece of debris in our DNA and has no influence on our organism.”

He moved the two sets of papers apart and put a third between them.

“Now take a look at this middle sequence.”

Sharko squinted. The new sequence was again nearly identical to the others. But there were far fewer highlighted letters, at most about twenty per page. A sequence very close to that of Cro-Magnon but not entirely identical either. Sharko looked at Lemoine with a concerned face.

“This is the virus that infected Félix Lambert, isn't it? It's what you found in his brain.”

The biologist nodded.

“Precisely. On the left is the sequence you brought us. In the middle, the one we found in Lambert's brain cells. And on the right, the harmless sequence we all share today. Moving from left to right, you see an increase in the number of anomalies. Now come have a look through this electron microscope.”

Sharko put his eye to the lens. He saw a large, black ball in the center, surrounded by twisted filaments like barbed wire, with two longer strands that made it look like a jellyfish, a Portuguese man-of-war. It was ugly, monstrous, and seemed to be gliding calmly in a sea of oil. Sharko's hair stood on end. The microscopic world was glacial and frightening.

“Meet GATACA,” said Lemoine. “It's the name we've provisionally given the pathogen present in Lambert's cell tissue. This is an ancestral virus, slightly mutated, since it shows a few anomalies, as you saw on those pages. Its genome contains exactly eight hundred thousand twelve ATGC bases—it's barely smaller than AIDS. Naturally, we still don't know how it works or replicates itself. Looking at what we found in Félix Lambert's organism, we think GATACA slowly and quietly invades the cells of the human body—and more specifically, the brain cells—over a period of years, like HIV. Then it moves into attack mode when its host reaches adulthood, somewhere around twenty. It's too early to tell if it's the secretion of hormones that triggers it, or the biological clock, or cell aging. All we know is that, from that point on, it begins a highly accelerated cycle: it multiplies at a prodigious rate in the brain's nerve cells, especially the surface areas, and disrupts everything in the host, a little like MS or Alzheimer's. We know what happens then. The individual has problems with balance, he becomes aggressive and commits violent acts . . .”

Sharko empied his coffee with a grimace. His throat felt dry.

“Is it contagious?”

“Not by breathing or through contact, but perhaps sexually. We just don't know. Another thing we don't know is if it works differently in men and women. We don't know how or when GATACA got into Félix Lambert's system. Nor do we know who created GATACA. According to Terney's book, Grégory Carnot was carrying the virus, and at least five others are in the same boat. But why them in particular? We'll need weeks, even months to understand all this and figure out how to stop it. Can you imagine the damage it could cause, especially if it
is
transmitted through sexual contact? The number of people infected could grow exponentially.”

He picked up the pages Sharko had given him.

“What you've discovered here is fundamental. This sequence you gave us seems to be the original, pure, unmutated form. It might be even more violent and harmful, and it might spread more easily. Today we know how to manufacture and grow viruses. Given what we already know of the damage GATACA can cause, can you imagine the monstrosities that could be unleashed by someone holding the recipe—the genetic sequence—for such a prehistoric virus?”

“You mean administering it to people without their knowledge? Contamination?”

“Sure. As well as being spread through sexual activity or handed down genetically.”

“From parents to children . . .”