Chen shrugs. "Seemed like the lesser of two evils. We had to get some track on what it was doing. Better than letting it see us."

"And if it triangulated on your pings?"

"We kept moving. Gapped the pings nice and wide. The most it could've known was that something was scanning the water column, and we've got a couple of things out there that do that anyway." Chen gestures at the screen, a little defensively. "It's all there in the track."

Lubin grunts.

"Okay, here's where it happens," Alexander says. "About thirty seconds from now."

The AUV is fading in the haze, apparently heading towards one of the few streetlights that actually pokes above the surface of Impossible Lake. Just before it disappears entirely, a black mass eclipses the view; some ragged outcrop intruding from the left. No circles of light play across that surface, even though the sub is obviously mere meters away; Chen and Alexander are running dark, hiding behind the local topography. The view on the screen tilts and bobs as their sub maneuvers around the rocks: dark shadows on darker ones, barely visible in the dim light backscattered around corners.

Alexander leans forward. "Here it comes…"

Light ahead and to the right; the far end of the outcropping cuts the edges of that brightening haze like a jumble of black shattered glass. The sub throttles back, moves forward more cautiously now, edges into the light—

—and nearly collides with the AUV coming the other way.

Two of the telemetry acronyms turn bright red and start flashing. There's no sound in the playback, but Clarke can imagine sirens in the sub's cockpit. For an instant, the AUV just sits there; Clarke swears she sees its stereocam irises go wide. Then it spins away—to continue its survey or to run like hell, depending on how smart it is.

They'll never know. Because that's when something shoots into view from below camera range, an elongate streak like a jet of gray ink. It hits the AUV in mid-spin, splashes out and wraps around it, shrinks down around its prey like an elastic spiderweb. The AUV pulls against the restraints but the trailing ends of the mesh are still connected to the sub by a springy, filamentous tether.

Clarke has never seen a cannon net in operation before. It's pretty cool.

"So that's it," Alexander says as the image freezes. "We're just lucky we ran into it before we'd used up the net on one of your monster fish."

"We're lucky I thought to use the net, too," Chen adds. "Who'da thunk it would come in so handy?" She frowns, and adds, "wish I knew what tipped the little beast off, though."

"You were moving," Lubin tells her.

"Yeah, of course. To keep it from getting a fix on our sonar signals, like you said."

"It followed your engine noise."

A little of the cockiness drains from Chen's posture.

"So we've got it," Clarke says. "Right now."