“It was a kill switch,” said Heron. “If the Partials ever got out of hand, boom: Activate the Failsafe, problem solved.”

“That’s a really good idea,” said Afa, heavily doped on painkillers but still relatively lucid. His thoughts all seemed clear, but his voice was slurred and his inhibitions, if he had any, were missing altogether. “Aside from the genocide, of course. No offense.”

“You’re a sweetheart,” said Heron, though her face told a different story.

“So the Failsafe was built into us,” said Samm. “It was a biological self-destruct button.”

“Which killed the wrong people,” said Afa.

“I don’t think so,” said Kira. She held up the screen and flipped through the file tree, looking for a specific one; when she found it, she held it up for all to see. “Here’s a cached email from the earliest days of the RM epidemic, attached to an article about a mystery disease that seemed to appear out of nowhere; the records don’t say exactly when the Failsafe was activated, or who did it, but my guess is that it happened about three days earlier. This particular email is from Nandita to my father.” She turned the screen back toward herself and read out loud, “‘New Super-Disease Claims Seven Human Lives in San Diego. Dozens of other cases may be related.’” She looked up. “The body of the email just says, ‘Quicker than we thought.’ Not ‘Oh no, it’s targeting the wrong people,’ just ‘Quicker than we thought.’”

“So they may have targeted humans on purpose,” said Samm. “Which . . . doesn’t make any sense at all.”

“No, it doesn’t,” said Kira, “which is why I’m not sold on the idea yet, I’m just pointing out that it’s a possibility.”

“Are you going to speculate wildly on the rest of the information?” asked Heron. “Or just this part? I want to know when I should start paying attention again.”