"Alan, the most dangerous thing here is catching a fever," said Quentin Fletcher, the oldest among them.

"That's right—you really have to be careful," the youngest, Evan Nash, added at once.

Ray's heart stirred. "Why?"

"The researchers here say there's a virus in the air now. Once your immunity drops, you get infected—either a high fever or a low-grade one. And once you have a fever, you're basically done for."

"Yeah, anyone who gets a fever is isolated. Most of them don't last ten days befo