Germ

Allen looked down. Blood had drizzled down his chest. He touched his fingers to his face. Lots of blood. He felt his cheeks, hoping it wasn't coming from his eyes.

"You have a nosebleed," Litt said. "It happens."

Allen took the handkerchief, wiped his hands and his face, and held it firmly to his nostrils.

"DNA," Litt said. "The complex molecule is a hereditary blueprint that defines a person's skin pigment, eye color and shape, hair color and texture, height, bone structure—every physical trait, including genetic diseases. Each DNA strand is made up of six billion repeating chemical units called nucleotides, consisting of one of four different kinds of chemicals called bases—A for adenine, C for cytosine, G for guanine, and T for thymine. So an individual's genome could be expressed GTTCGTCAAATTG . . . and so on for six billion letters. No two people share the exact same sequence. Twins are close, but still unique. Interestingly, nature—" He held a up a conciliatory hand. "Or God. I understand your brother is a priest."

"A pastor," Allen said flatly.

"Well, then . . . God put markers in generally the same spots on our DNA strands. These markers are the same in everybody. They're like road signs that tell us what the subsequent DNA codes are for— height, hair color, Huntington's disease, obesity. These markers simplify the process of finding sequences unique to specific individuals.

How many thugs are doing time because they left a bit of their DNA at a crime scene—blood, semen, skin, hair roots?"

"All right," Allen said. "DNA is unique and identifiable. That doesn't explain—"

"Now, now, Dr. Parker. This is fascinating stuff, if you hear me out." He cleared his throat. "I'm sure you're more versed in the ways of viruses. To refresh: A virus is designed to survive. Whatever it needs to replicate itself—to propagate the species, if you will—it will do. That may mean mutating to avoid a threat, such as an antibody, or to avoid competition from a stronger virus. That's why we have so many different ones. Herpes viruses seek out the cells of nerve tissue, the avian flu virus goes right for the alveoli cells, deep in the lungs. A virus is like a key looking for the cell with a matching lock. When it finds the right cell, it unlocks it and strolls on in, a thief with a key to the jewelry store. The virus tells the cell's DNA to stop what it's doing and focus on replicating the virus. So now a cell is destroyed, and the virus multiplies. In Ebola's case, the cells it commandeers happen to be the ones that hold together blood vessels and organs.

"Since we know that a virus has the ability to find what it needs, why not tell it what it needs? Gene splicing is a fairly simple matter these days. The technology exists, for instance, to take out the gene that codes for brown eyes and literally stick in the gene that codes for blue eyes. However, I did not change what the Ebola virus looks for— the lock that fits it. I simply added another lock. When Ebola finds a tissue cell it would normally unlock, it encounters a second lock and can't get in. That other lock is a specific individual's DNA, just enough of a sequence to differentiate that person from all but a few other people in the world. I splice that sequence into the section of the Ebola DNA that tells it what to look for, part of its glycoprotein gene. Now, it looks for only the endothelial cells of the person I told it to find. When both keys match, it takes over the cells, replicates, and essentially becomes full-blown Ebola. Or, more precisely, Ebola Kugel. Kugel means "bullet" in my native tongue. A bullet instead of a bomb." His lipless mouth bent upward.

Allen thought a moment. "You've got Ebola piggybacking on a common cold virus?"

Litt nodded. "Rhinovirus. It can move across the country in twenty-four hours. But Ebola is not so much hitching a ride as it is spliced into it. That way it replicates with the cold virus. I'm making it all sound very easy," he said with a wave of his hand, "but it's infinitely complicated, I assure you. If it weren't, someone else would have already done it." He slapped Allen's leg with his skeletal hand. "Now then. Why am I telling you all this?"

When Allen said nothing, he continued. "To convince you I know what I'm doing. None of this is an accident. I am in complete control. So believe what I say now." He bowed his head closer to Allen and whispered, "I have the cure."

Hope moved through Allen like adrenaline. He tried to suppress it, hold it down, but his heart thumped faster, his stomach tightened in anticipation.

"There is no cure for Ebola," he said.

Litt rolled his head, exasperated. "Have you heard a word I've said? Ebola also doesn't seek out specific individuals—but look at you. In fact, Ebola did not exist at all until I created it. Since I intend to use it against my enemies, would knowledge of a cure be something I shared?"

"So why tell me?"

"You have something I want. I'm negotiating."

"Vero's memory chip."