“What decision?” asked Wren.

“The decision about whether or not you tell your parents and your friends what you’ve seen here tonight.”

Wren thought she trusted him, but she wasn’t sure. She had never had to think about trusting people before. Confused by Gargle’s smile, she looked past him down the beach. The water between the headlands was shining blue. She thought at first that it was just the afterimage of the flashlight on her eyes, but then the blue grew brighter, and brighter still, and she saw that it was a light shining up through the water from below. Something huge broke the surface about thirty feet offshore.

Behind Caul’s shack in the engine district, the limpet that had brought him to Anchorage lay rusting. It was called the Screw Worm, and Wren and her friends had often played hide-and-seek between its crook-kneed legs when they were children. She had always thought it a comical sort of thing, with its big flat feet and its windows at the front like boggly eyes. She had never imagined how smoothly a limpet would move, how sleek its curved hull would look, moonlight sliding off it with the water as it waded to the beach.

This limpet was smaller than the Screw Worm, and its body was flatter, more like a tick’s than a spider’s. Wren thought it was painted with jagged camouflage patterns, but it was hard to be sure in the moonlight. Through the bulging windows she could see a small boy working the controls, his face distorted by the water draining down the glass. He brought the machine to a stop at the water’s edge, and a ramp came down out of its belly with a shush of hydraulics and grated against the shingle there.

“The limpet Autolycus,” said Gargle, gesturing for Wren to go aboard. “Pride of the Lost Boy fleet. Come aboard, please. Please. I promise we won’t submerge until we’ve put you ashore.”