Clarke remembers: there are transponders in every hab, every drone and vehicle down here. They talk nicely enough to each other, but they'll scream to wake the dead should sonar touch anything that doesn't know the local dialect. Clarke hasn't thought about them for years; they hail from the early days of exile, when fear of discovery lay like a leaden hand on everyone's mind. But in all this time the only enemies they've found have been each other.

"Strange they haven't tried, though," Clarke says. It seems like an obvious thing to do.

"Maybe they tried and lost us," Hopkinson suggests. "If they got too close we'd see them, and there's spots along that route where sonar barely gives you sixty meters line-of-sight."

"Maybe they don't have the resources," Alexander says hopefully. "Maybe it's just a couple of guys on a boat with a treasure map."

Nolan: "Maybe they just haven't got around to it yet."

"Or maybe they don't have to," Lubin says.

"What, you mean..." Something dawns on Hopkinson's face. "Pest control?"

Lubin nods.

Silence falls around the implications. Why spend valuable resources acquiring and following your target through territory which might be saturated with tripwires? Why risk giving yourself away when it's cheaper and simpler to trick your enemies into poisoning their own well?

"Shit," Hopkinson breathes. "Like leaving poisoned food out for the ants, so they bring it back to the queen…"

Alexander's nodding. "And that's where it came from…ßehemoth was never supposed to show up anywhere around here, and all of a sudden, just like magic…"

"ß-max came from goddamned Atlantis," Nolan snaps. "For all we know the strain out at the Lake's just baseline. We've only got the corpses' say-so that it isn't."

"Yeah, but even the baseline strain wasn't supposed to show up out there—"

"Am I the only one who remembers the corpses built the baseline in the first place?" Nolan glares around the room, white eyes blazing. "Rowan admitted it, for Chrissakes!"

Her gaze settles on Clarke, pure antimatter. Clarke feels her hands bunching into fists at her side, feels the corner of her mouth pull back in a small sneer. None of her body language, she realizes, is intended to defuse the situation.

Fuck it, she decides, and takes one provocative step forward.

"Oh, right," Nolan says, and charges.

Lubin moves. It seems so effortless. One instant he's sitting at the console; the next, Nolan's crumpling to the deck like a broken doll. In the barely-perceptible time between Clarke thinks she saw Lubin rising from his chair, thinks she glimpsed his elbow in Nolan's diaphragm and his knee in her back. She may have even heard something, like the snapping of a tree branch across someone's leg. Now her rival lies flat on her back, motionless but for a sudden, manic fluttering of fingers and eyelids.

Everyone else has turned to stone.