He now had points of proximity or actual contact and, presumably, opportunities for viral transmission. The pattern he saw emerging was already clear, but he refused to jump to conclusions. He did not trust either intuition or instinct. He trusted hard facts, indisputable associations, and repeated correlations.
He drew the results a second way, in columns and rows. When he had completed his chart, he drew a new table, reversing the order, and filled the boxes with the categorized numbers.
Dicken cleaned up his work and tapped the plastic end of the pen on the columns, marching down, climbing back up, sweeping the marker to the right across the rows, color-coding the associations.
Any way he drew it out, the pattern was clear.
Within the special treatment center, children who had had no contact with teachers or other students for more than three days had not contracted the virus. Eight children had been in isolation cells and had been abandoned when the staff evacuated. Three had died, but all of their specimens tested negative.
Five hours ago, Middleton had phoned the lab to tell Dicken that one of the rescued children had fallen ill, and Kelson said she was likely to die. That child had almost certainly been exposed after her “rescue.”
Dicken had taken specimens from six children who had been locked in a shower room by a fleeing teacher, and not found until late yesterday. One had died from lack of special medication. None had had any contact with teachers or staff for the past forty-eight hours. Their specimens tested negative.
DeWitt and Middleton had identified fifty children whom they knew had had close contact with teachers and staff in the past sixty hours. Of these, forty had fallen ill, and twenty had died. All of their specimens tested positive. Somehow, ten had managed to avoid exposure.
He looked over the results for twenty-two teachers, staff, and security officers. All had had continuous contact with infected children for the past forty-eight hours. They were exhausted, stressed, worn down. Six of these—four nurses from the main pool and one teacher from the special treatment wing, and the counselor, Dewitt—tested positive for the virus, but in low titers compared to infected children. None showed symptoms of infection.
Neither he nor Mark Augustine tested positive.
Dicken held up his chart once more. The conclusions were compelling.
Only infected SHEVA children showed symptoms.
SHEVA children lacking recent adult contact tested negative for the virus and showed no symptoms.
Contagion did not spread from the children to adults with much efficiency, if at all; and if it was passed on, did not cause illness in adults.
Contagion probably didspread from child to child, but the chain always began with children who had had recent contact with adults.
He had not gathered specimens from every child, alive or dead, or from all the adults that had been at the school; it was possible that an asymptomatic child was the source; it was also possible that exposed adults would get ill, eventually.
But he doubted it. The children were almost certainly not the source. And adults did not get sick. The river flowed in only one direction, downstream from teachers and staff, adults, to the new children.
The computer chimed again. Dicken looked at the screen. The Ideator had identified a sequence from its standard human genomic library. He touched a box on the screen. It expanded outward, showing a gene map for an obscure and defective HERV. Coxsackie viruses—for that matter, the superfamily of Picornaviridae—had never been known to recombine with legacy retroviral genes. Yet he was looking at a protein traced to a gene from the suspect virus, and it was very similar—90 percent homologous—to a protein once coded for by an ancient human endogenous retrovirus found in two chromosomes.
The presence of the protein converted a relatively benign RNA virus into one that killed, in large numbers.
He typed in another search. The Ideator scanned the Genesys bank for a match within the 52-chromosome genome of the new children. According to the Genesys bank, that particular defective primordial HERV did not exist in any SHEVA child.
Both of its copies had been discarded during the supermitotic splitting and rearrangement of the old chromosomes.
Dicken stared at the screen for several minutes, thinking furiously. His vision blurred. He grabbed the crumpled wipe and dabbed again at his face. His left leg cramped. He pushed away from the bench and walked around the small lab room, bracing on tables, equipment.
What Augustine and the Emergency Action people feared most had happened. Ancient viruses had somehow self-corrected and contributed one or more novel genes to a common virus, producing a deadly disease. But the recombination had not taken place in SHEVA-affected children.
It had begun in adults.
Adults were creating viruses that could infect and kill the SHEVA children. Those same viruses did not harm the adults. Dicken could yet be sure, but he suspected that the viral protein took advantage of yet another protein expressed only in the children—two units not in themselves toxic, but lethal in combination.
A new role for viruses: agents of a species-level immune response. Biological warfare, one generation against another.
An old species trying desperately to kill the new? Or just an awful mistake, a slip-up with deadly consequences?
He secured the samples, backed up the computer files, made a set of printouts, locked up the lab, and brutally shoved the outer door of the research building. It slammed open, and he walked out into the glare of the afternoon sun.
50
PENNSYLVANIA
Mitch had put on one of George Mackenzie's white terry robes to check on Stella. He now lay on the bed beside Kaye, the robe ridiculously short over his long legs. His breathing was even. She could feel his hand, large and wide, with long, thick fingers, resting on her arm.
Kaye rolled over and put her head on his chest, where the robe had pulled open. “Have I been acting a little crazy?” she asked.
Mitch shook his head. “Defensive.”
“Do you remember before we were together? You were doing archaeology. I was working away madly, and confused.”
“I wasn't doing much archaeology,” Mitch said. “I've been out of action for longer than I've known you. My own damned fault.”
“I loved your rough hands. All the calluses. What would we be without Stella?”
Mitch's eyes narrowed. Wrong question.
“Right,” Kaye said. She lay back on the pillow. “I insisted. We don't have any other life now.”
“I helped,” Mitch said.
“I've neglected you. In so many ways.”
Mitch shrugged.
“What do you want for Stella?” Kaye asked.
“A reasonably normal life.”
“What will that be? She isn't like us, not really.”
“She's more like us than she's different.”
Kaye wiped her eyes with the back of her hands. She could still feel the caller, and when she touchedit with her thoughts, waves of comfort surged through her and her eyes flowed over. She could not understand this feeling of glorious ease in the midst of their fear.
Mitch touched her cheek. His finger gently dabbed the wet corner of one eye.
“What's it like to have a stroke?” she asked. “Or a seizure?”
“You're the doctor,” Mitch said, taken aback.
“Sam had a stroke,” Kaye said. Sam was Mitch's father.
“He went down like a tree,” Mitch said.
“He was paralyzed and he died in a couple of hours.”
“It was fast. What are you getting at?”
“Do people have seizures that make them feel good? They wouldn't go to the doctor for that, would they?”
“I've never heard of such a thing,” Mitch said.
“But it wouldn't be reported, would it, unless they happened to catch it . . . on an MRI or CAT scan or something. The brain is so mysterious.”