"Lenie. Ken. Where are you going?"

Seger's voice, this time. Klein's called for reinforcements.

"We thought we'd come for a visit," Lubin says.

"Are you sure you've thought that through?" Seger says calmly. "With all due respect—"

"Is there some reason we shouldn't?" Lubin asks innocently.

"Lenie's l—"

"Beyond Lenie's leg."

Dead air in the room.

"You've analyzed the samples by now," Lubin remarks.

"Not comprehensively. The tests are fast, not instantaneous."

"And? Anything?"

"If you were infected, Mr. Lubin, it only happened a few hours ago. That's hardly enough time for an infection to reach detectable levels in the bloodstream."

"That's a no, then." Lubin considers. "What about our 'skins? Surely you would have found something on the diveskin swabs."

Seger doesn't answer.

"So they protected us," Lubin surmises. "This time."

"As I said, we haven't finished—"

"I understood that ßehemoth couldn't reach us down here," he remarks.

Seger doesn't answer that either, at first.

"So did I," she says finally.

Clarke takes a half-hop towards the airlock. Lubin offers an arm.

"We're coming over," he says.

Half a dozen modelers cluster around workstations at the far end of the Comm Cave, running sims, tweaking parameters in the hopes that their virtual world might assume some relevance to the real one. Patricia Rowan leans over their shoulders, studying something at one board; Jerenice Seger labors alone at another. She turns and catches sight of the approaching rifters, raises her voice just slightly in an alarm call disguised as a greeting: "Ken. Lenie."

The others turn. A couple of the less-experienced back away a step or two.

Rowan recovers first, her quicksilver eyes unreadable: "You should spare that leg, Lenie. Here." She grabs an unused chair from a nearby station and rolls it over. Clarke sinks gratefully into it.

Nobody makes a fuss. The assembled corpses know how to follow a lead, even though some of them don't seem too happy about it.

"Jerry says you've dodged the bullet," Rowan continues.

"As far as we know," Seger adds. "For now."

"Which implies a bullet to dodge," Lubin says.

Seger looks at Rowan. Rowan looks at Lubin. The number crunchers don't look anywhere in particular.

Finally, Seger shrugs. "D-cysteine and d-cystine, positive. Pyranosal RNA, positive. No phospholipids, no DNA. Intracellular ATP off the scale. Not to mention you can do an SEM of the infected cells and just see the little fellows floating around in there." She takes a deep breath. "If it's not ßehemoth, it's ßehemoth's evil twin brother."

"Shit," says one of the modelers. "Not again."

It takes Clarke a moment to realize that he's not reacting to Seger's words, but to something on the workstation screen. She leans forward, catches sight of the display through the copse of personnel: a volumetric model of the Atlantic basin. Luminous contrails wind through its depths like many-headed snakes, bifurcating and converging over continental shelves and mountain ranges. Currents and gyres and deep-water circulation iconised in shades of green and red: the ocean's own rivers. And superimposed over the entire display, a churlish summary:

Failure to converge. Confidence limits exceeded.

Further predictions unreliable.

"Bring down the Labrador Current a bit more," one of the modelers suggests.

"Any more and it'll shut down completely," another one says.

"So how do you know that isn't exactly what happened?"

"When the Gulf Stream—"

"Just try it, will you?"

The Atlantic clears and resets.

Rowan turns from her troops and fixes Seger. "Suppose they can't figure it out?"

"Maybe it was down here all along. Maybe we just missed it." Seger shakes her head, as if skeptical of her own suggestion. "We were in something of a hurry."

"Not that much hurry. We checked every vent within a thousand kilometers before we settled on this site, did we not?"

"Somebody did," Seger says tiredly.

"I saw the results. They were comprehensive." Rowan seems almost less disturbed by ßehemoth's appearance than by the thought that the surveys might have been off. "And certainly none of the surveys since have shown anything…" She breaks off, struck by some sudden thought. "They haven't, have they? Lenie?"

"No," Clarke says. "Nothing."

"Right. So, five years ago this whole area was clean. The whole abyssal Atlantic was clean, as far as we know. And how long can ßehemoth survive in cold seawater before it shrivels up like a prune and dies?"

"A week or two," Seger recites. "A month max."

"And how long would it take to get here via deep circulation?"

"Decades. Centuries." Seger sighs. "We know all this, Pat. Obviously, something's changed."

"Thanks for that insight, Jerry. What might that something be?"

"Christ, what do you want from me? I'm not an oceanographer." Seger waves an exasperated hand at the modelers. "Ask them. Jason's been running that model for—"

"Semen-sucking-motherfucking stumpfucker!" Jason snarls at the screen. The screen snarls back:

Failure to converge. Confidence limits exceeded.

Further predictions unreliable.

Rowan closes her eyes and starts again. "Would it be able to survive in the euphotic zone, at least? It's warmer up there, even in winter. Could our recon parties have picked it up and brought it back?"

"Then it would be showing up here, not way over at Impossible Lake."

"But it shouldn't be showing up anywh—"

"What about fish?" Lubin says suddenly.

Rowan looks at him. "What?"

"ßehemoth can survive indefinitely inside a host, correct? Less osmotic stress. That's why they infect fish in the first place. Perhaps they hitched a ride."

"Abyssal fish don't disperse," Seger says. "They just hang around the vents."

"Are the larvae planktonic?"

"Still wouldn't work. Not over these kinds of distances, anyway."

"With all due respect," Lubin remarks, "you're a medical doctor. Maybe we should ask someone with relevant expertise."

It's a jab, of course. When the corpses were assigning professional berths on the ark, ichthyologists didn't even make the long list. But Seger only shakes her head impatiently. "They'd tell you the same thing."

"How do you know?" There's an odd curiosity in Rowan's voice.

"Because ßehemoth was trapped in a few hot vents for most of Earth's history. If it had been able to disperse inside plankton, why wait until now to take over the world? It would have done it a few hundred million years ago."

Something changes in Patricia Rowan. Clarke can't quite put her finger on it. Maybe it's some subtle shift in the other woman's posture. Or perhaps Rowan's ConTacts have brightened, as if the intel twinkling across her eyes has slipped into fast-forward.

"Pat?" Clarke asks.

But suddenly Seger's coming out of her chair like it was on fire, spurred by a signal coming over her earbud. She taps her watch to bring it online: "I'm on my way. Stall them."

She turns to Lubin and Clarke. "If you really want to help, come with me."

"What's the problem?" Lubin asks.

Seger's already halfway across the cave. "More slow learners. They're about to kill your friend."