Brisling crossed another city off the map. He had bought it in the hotel gift shop, a big poster of the globe intended for young children, all camels and pyramids and zebras and smiling people with diverse skin tones. Some of the countries were misshapen, too big or too small, a few cities mislabeled, but the map had served its purpose.

He had crossed off seventy cities in all—one for each public utilities official who had actually picked up the phone—seventy different versions of the same response: "You want what?" Yes, Brisling answered, and send it to my lab at King County Hospital in Seattle by the fastest means possible. If only half of them kept their promise, it would be enough for his experiment. Hindsight is twenty-twenty, but foresight is one in a million.

Now he unplugged his cell phone from the wall charger and fixed his tie in the mirror. Genevieve had new data, and she wanted Brisling in her office right away. He straightened his freshly pressed brown suit, wondering why he had even bothered sending it down to the hotel laundry. Its crisp edges and sharp lines only made him look older, balder, fatter.

As he strolled through the warm Atlanta afternoon, the people around him, the birds, the trees even, all seemed to hush at his passing, as if they were straining to hear the story still playing out in his head.

Sink or swim, Genevieve had said that night when she found him in his office with a bottle of bourbon and a handful of sleeping pills. Live or die. She had tossed out those words and waited for him to take hold. Even now, all these years later, he wondered why he had. Eighteen months later, on the second anniversary of Judith's death, DEA agents raided Brisling's laboratory and office, seizing records and arresting a young male technician Brisling had hired at the recommendation of a colleague. Unknown to Brisling, the technician had been forging his signature and using his federal grant dollars to buy research-grade cocaine and amphetamines from chemical-supply companies. Most of the drugs, the technician sold on the street. The rest he snorted right there in the lab, high as a kite every day.

In the eyes of the federal government, responsibility lay with Brisling, even if he could not remember the technician's name. Under a settlement, the criminal charges were dropped, but Brisling and the CDC were forced to repay the US government nearly a half million dollars in defrauded research funds. The taxpayers got their pound of flesh. But because the technician's data was untrustworthy, blatantly falsified in many instances, Brisling also had to retract a dozen high-profile publications. Suddenly, no one wanted to fund his research. One by one his colleagues and his army of assistants deserted him, fearful of his stain, his scarlet letter—F for fraud. Eventually, Brisling packed his things and headed west, to Seattle, hoping for a fresh start. But the shadow of Atlanta was long.

Genevieve was sitting at her desk when Brisling arrived. The air in her office was tight, humid with perspiration and the odor of permanent marker. From the walls hung a dozen banners made from sheets of white paper taped end to end, the endless lines of print marked up with red, blue, and green ink.

Brisling craned his neck. "Is this the DNA sequence from the virus?"

Genevieve looked up, reading glasses perched on the tip of her broad, lovely nose. "Double-spaced, twelve-point Helvetica font, just like you asked."

"Where's the lab tech?"

"Right here," said Lisa from behind the door. She was kneeling on the floor and marking one of the printouts with a green felt-tipped pen, her outrageous mane of kinky blond hair bouncing all over the place. "This is the entire sequence. Twelve kilo-bases."

Brisling closed the door. "That's twice the size of JCV's genome."

"I know. Only about thirty percent of the DNA sequence lines up with JCV, mostly in the viral coat genes. That's why my primers picked it up. But other than that, it's completely different."

"Any similarity with other viruses?"

"Not any virus in the NCBI database. I ran a full BLAST search."

"So what the hell's in the other seventy percent of the DNA?"

"Protein-coding sequences, mostly."

Brisling's eyes darted from banner to banner. "Do any of them happen to encode zinc finger proteins?"

Lisa got to her feet. "Yeah. There's one. How did you know?"

"I've had some time to think about this. What do zinc finger proteins do?"

"They bind DNA and control its activation."

"Exactly."

"Oh, I get it."

Genevieve sighed noisily and took off her glasses. "I'm an epidemiologist, not a molecular biologist. Will one of you please explain what on earth you're talking about?"

Lisa nodded. "The zinc finger protein made by our new virus might latch onto the DNA of dormant JCV virus in people's brains and reactivate it, you know, wake it up. That's why healthy people are getting sick."

"A virus turning on another virus?"

"It's called a helper virus," said Brisling.

Genevieve tilted her head. "OK. That might explain why JCV is reactivating in most people, but what about Native Americans? Why would they be immune to the effects of this new virus?"

"Simple," said Brisling. "Remember what I said before, how each major racial group carries its own unique JCV strain, or genotype? Well, genotype 2 carried by Native Americans must be resistant to reactivation. Even a slight variation in its DNA sequence could render it resistant to the helper virus's zinc finger protein." He clapped his hands together. "Yes. That has to be it."

Lisa shook her head, big hair wobbling for a second or two afterward. "I'm not so sure, Dr. Brisling."

"Do you have a better explanation?"

"No, that's not what I meant." She pointed with her green pen. "It's what I was marking when you walked in. The zinc finger sequence isn't complete. It's actually split into two halves, one near the beginning and other at the end. It wouldn't make a complete protein, not in this form."

Brisling began to sweat. Stripping off his jacket, he tossed it onto the chair and stood in the center of the office, taking in the dangling banners taped to the walls, all the colorful markings Lisa had made. "What are those short sequences you underlined in red?"

"Have a look for yourself."

Brisling got on his toes and traced one of the sequences with his fingertip, armpit damp with sweat. At first, it seemed nothing more than a random sequence of capital As, Ts, Gs, and Cs—the four units of the genetic code. Then the pattern snapped into place. "Jesus Christ, that's a palindrome."

"A what?" said Genevieve.

"A palindrome," Lisa explained. "A DNA sequence that reads the same forward and backward." Then to Brisling she said, "I've found twelve so far. Two of them link the zinc finger sequences to tandem repeats at either end of the virus's genome."

Brisling settled back down on his heels, finger still pinned to the paper. "Tandem repeats? Palindromes?" He lowered his arm and took two steps back, doing a slow three-sixty. "Son of a bitch. They actually did it. Son of a bitch!"

"I know. The palindromes are restriction enzyme sites," said Lisa.

Genevieve threw her arms in the air. "Tandem bikes on a velodrome! Will one of you tell me what on Earth you're talking about?"

"It's basic molecular biology," said Lisa. "Restriction enzyme sites are specific palindromic DNA sequences we use in the lab to splice DNA—like an editor splices film for a movie."

"What are they doing in this virus?"

Brisling answered, his voice low and cool. "They're the seams in the viral genome. They're where it was stitched together."

Genevieve shot to her feet. "It's man-made?"

Brisling raised his index finger. "What was it you were saying yesterday, something about it not following the rules of nature?"

"Good Lord. Is this some sort of bioterrorism weapon?"

"It could be," said Brisling. "But if I had to put money on it, I'd say it escaped from a lab somewhere. This thing's way too subtle for terrorism."

"And too slow," Lisa added.

Brisling whipped around. "What do you mean by that?"

She pointed to a sequence underlined in blue at the top of the very first banner. "That's one of the tandem repeats I was talking about. Don't you recognize the sequence?"

Again, Brisling stood on his toes. TTAGGG. "Is that what I think it is?"

"A telomere."

This time, Brisling explained before Genevieve could protest. "Telomere sequences are like molecular clocks that cap the ends of normal human chromosomes. Each time a cell divides, the telomere erodes a little, and the chromosome becomes more unstable. It's the molecular basis of aging." He stood next to Lisa, his head tilted back with hers. "What would happen if the telomeres at either end of this genome completely eroded away, say after twenty-five years?"

"It would expose the palindromic sequences at either end, and—"

"Bring together the two halves of the zinc finger sequence, forming a functional gene, which would produce a functional protein that could activate JCV." Brisling turned to Genevieve. "It's a goddamned molecular time bomb. Jesus, no wonder no one under the age of twenty-five is getting sick. They haven't had time yet. This thing's a man-made sleeper virus with a fuse a quarter-century long!"

Genevieve picked up her desk phone and began to punch in a number. "De Soto needs to hear about this right away."

Brisling stumbled back and fell into the chair, crushing his freshly pressed jacket. "Go ahead," he said with a wave of his hand. "It won't make any difference."

She put the receiver to her ear. "He'll listen to me now. With what you two have discovered, he'll listen."

"No," he said, removing his glasses and massaging his temples. "It's already too late."

____________

Gif image: DNA double helix. Taken from Wikimedia Commons