The pumps make a sound like a thoughtful refrigerator. Minnow’s skids kiss the pool rim, then hang. Near-neutral. Reed flicks your ear, fond. “That’s a fish. Don’t make it a brick or a balloon.”

Vargas fills the hatchway. “Good. Now we spend that fish on a plan, not a feeling. Sonar has a grid if you’ll use it. Or—” and here Vargas’s mouth goes thin, “someone suggested we blow Nereid’s own ballast and rise for a look, like this house is a periscope. I will hear you say why not, or I will hear you say why, and then I will be disappointed in stereo.”

You glance at the moon pool. The silver square is the whole ocean’s lid, held down by physics, not hope. Habitat tanks are for sitting, not sightseeing. Air that lifts you here will lift you harder as you go up, because bubbles grow when the mountain of water gets shorter.

Reed mutters, “Corks don’t take samples.”

TIDE: “Habitat positive buoyancy without flood-back procedure is not an approved search method.”

Approved is a love word in a place like this.