Kevin grabbed a pad of paper. “Give me a few minutes and I’ll pull it together.”

Just as Kevin headed off to record the readings from the dozens of stations scattered around the lab, Nate walked in. Juan wondered if the agent knew what was planned for the quarantined sites.

“How’s it going, Juan?”

“It’s going.” Juan nodded toward Kevin. “He’s tabulating some data for me now.”

“Do you think you might have a breakthrough?” Nate asked, sounding hopeful.

“No, not really something like that. We’re just trying to come up with a more surefire way to know if someone has been given this form of gene therapy.”

“Is it really that difficult?” Nate asked. “I’m no doctor, but if these people are suffering from a virus, isn’t it just a matter of identifying the antibodies the body produces?”

“Unfortunately, not in this case. With a normal virus, you’d be correct. An ordinary virus—like, say, a flu virus—invades cells, chews up their DNA to make copies of itself, then spreads itself everywhere. Like a bull in a china shop. The body sees these viruses as foreign invaders, and it responds by producing antibodies specific to that virus.

“But this virus is different. When it invades a cell, it merges its genetic code with the infected cell. Then later, when that cell naturally divides, the contents replicate. The body doesn’t create an antibody, because it doesn’t see an invader—just natural cell division.”

Nate frowned. “In that case, why does everyone who’s infected have a fever?”

Juan gave Nate an approving nod. “That’s the exact question I’ve been asking myself.”

“Dr. Gutierrez,” Kevin said, hurrying over. “I’ve gathered the data and have group-level averages.” He rubbed the back of his neck and held his notepad out at arm’s length. “There’s almost no difference between the exhalations of the dosed animals. However, the non-dosed animals had a lower CO2 and higher O2 level than the dosed ones.”

Juan’s eyes narrowed. “How big of a difference?”

“The dosed rats are putting out twice as much CO2 and about one-fourth less O2.”

“That’s great!” Juan exclaimed. He turned to Nate. “This could give us a reliable way of telling if someone has the virus.”

“Could, or does?” Nate asked.

“Well, I can’t be sure until I’ve tested it on people who are known to have the virus.” Hutchison’s warning about only having ten days loomed large in his mind. “If I set up a test rig, do you think I could be taken to one of the quarantine sites?”

Nate shrugged. “I’ll have to check with my supervisor. To be honest, I don’t even know where the sites are. When would you want to go?”

“That depends.” Juan turned to Kevin. “Kevin, please tell me we have portable capnography machines that’ll measure exhaled O2 and CO2.”