But here she is at the Throat, swimming along Main Street. The generators loom over her like sheltering giants. She bathes in their warm sodium glow, passes through clouds of flickering microbes, barely noticed. Beneath her, monstrous benthos filter life from the water, as oblivious to her as she is to them. Once she passes a multicolored starfish, beautifully twisted, stitched together from leftovers. It lies folded back against itself, two arms facing upward; a few remaining tube feet wave feebly in the current. Cottony fungus thrives in a jagged patchwork of seams.

At the edge of the smoker her thermistor reads 54°C.

It tells her nothing. The smoker could sleep for a hundred years or go off in the next second. She tries to tune in to the bottom-dwellers, glean whatever instinctive insights Acton could steal, but she's never been sensitive to invertebrate minds. Perhaps that skill comes only to those who've crossed the ten-percent threshold.

She's never risked going down this one before.

It's a tight fit. The inside of the chimney grabs her before she gets three meters. She twists and squirms; soft chunks of sulfur and calcium break free from the walls. She inches down, headfirst. Her arms are pinned over her head like black jointed antenna. There's no room to keep them at her sides.

She's plugging the vent so tightly that no light can filter in from Main Street. She trips her headlight on. A flocculent snowstorm swirls in the beam.

A meter further down, the tunnel zigs right. She doesn't think she'll be able to navigate the turn. Even if she can, she knows the passage is blocked. She knows, because a lime-encrusted skeletal foot protrudes around the corner.

She wriggles forward. There's a sudden roaring, and for one paralyzed moment she thinks the smoker is starting to blow. But the roar is in her head; something's plugging her electrolyser intake, depriving her of oxygen. It's only Lenie Clarke, passing out.

She shakes back and forth, a spasm centimeters in amplitude. It's enough; her intake is clear again. And as an added bonus, she's gotten far enough to see around the corner.

Acton's boiled skeleton clogs the passageway, crusty with mineral deposits. Blobs of melted copolymer stick to the remains like old candle wax. Somewhere in there, at least one piece of human technology is still working, screaming back to Beebe's deafened sensors.

She can't reach him. She can barely even touch him. But somehow, even through the encrustations, she can see that his neck has been neatly snapped.

Reptile

It has forgotten what it was.