The wall arrives without a knock.

One second the lamps make a coin of flakes. The next second the coin is basalt, pillow lava like a pile of burnt bread, too close to be a picture. Reed yanks a thruster. You yank the other. Newton is fair and not enough.

Minnow kisses the terrace with a sound you will hear later in sinks. The acrylic does not come in. The skid does bend. Trim dumps you heavy into a notch as if the seamount wanted a pet.

TIDE, from far away: “Sled wedged. Habitat tether intact. Crew vital signs nominal.”

Nominal is a love word that feels like a joke. You are not hurt beyond a shoulder that will be a story. Paz is still a quiet can. Gannet still cannot crane. Reed starts the checklist for “we live here now until someone un-pets us,” which is slow and undignified and safe.

Vargas: “Memory is not a chart. You will write that down.”

You write it. The lamps light a wall you could have measured.

THE END

What you learned: black water has walls. Lights are a short cough. Memory of a canyon is not a position. Sonar travel time is how you knock before you enter.