FeatherPenClipArt RSR rating: hard SF, 5 stars, published in Clarkesworld.

A woman repairing power cable for the underwater Sylvia City rescues a drowning boy. Carrying him to the surface, she finds infrastructure on the surface has been destroyed by a war. She outfits the boy for survival underwater and carries him to the outstation where she works, then goes back to destroy the underwater cable and surface power station so the drylanders can’t find Sylvia City.

This is also a sentimental story. Pawley doesn’t make as much use of the child as she could, as he never speaks. However, the heroine’s coworkers make sacrifices to help her carry out her mission.

Checking RSR’s criteria, I’ll agree that this one is hard SF. It’s got the clanking hardware, which is necessary to deal with living on the ocean floor. The science behind this isn’t over-explained, and suggests organic technologies. The “scalesuit” that the narrator wears is living, for example, as is the cable that she maintains and the snails that handle maintenance.

I do have some issues with disbelief, however. First of all, the narrator shoots to the surface of the ocean, carrying the boy. What about decompression? Presumably her scalesuit might take care of it, but what protects the boy? I’m not quite buying this. Also, I don’t understand the “carbon weapons” the drylanders use. RSR notes these are probably nanotech, but the story describes this as an airplane shooting a pulse which burns only living things to ash and creates a carbonic acid fallout (from CO2) that poisons the ocean. It sounds suspiciously like a death ray. If it is nanotech, why doesn’t it spread and kill everybody? Will it deactivate after a while, or do the different sides in the war have their own impregnable fortresses?