Night aboard a Republican gunboat in the Yangtze estuary blockade; the radio cabin is cramped, wet with condensation, and lit by a single oil lamp.

Shift change in the radio cabin. Male operators crowd around Lin, joking and checking equipment before leaving her on watch.

The watch-lock procedure begins, and Wei reminds Lin how little authority she has once the cabin is sealed.

Watch Officer Tang passes the cabin before the lock fully settles, establishing him as the officer whose stamp controls reports.

The cabin is now locked from outside. Lin settles into the ordinary rhythm of the night watch.

A routine coast-watcher burst begins, disguised as fish-market talk.

Lin copies the burst faster than anyone else could have, alone with the machine and the clock.

Lin reviews the first pass and finds nothing alarming at first.

On the second pass, Lin notices a word that does not belong among fish names.

Lin remembers her grandmother teaching a village fish-market cipher, a lesson never recorded in naval manuals.

Lin returns to the present and uses the village rule to read the hidden line.

The hidden phrase resolves into the name of the watch officer.

Lin checks the required report form and understands why the warning cannot move legally.

Lin tries to get the cabin opened, but procedure blocks her before she can explain.

Lin sees the transmission slot approaching and calculates the danger of every option.

Lin thinks of her younger brother and what a treason accusation would cost him.

Lin chooses not to send the true message. She prepares a harmless partial decrypt instead.

Lin edits the report so it looks routine while keeping the real message separate.

Lin hides the true decrypt in her sleeve as the outgoing slot nears.

The crew outside asks for the scheduled outgoing traffic, and Lin must sound normal.

Lin passes the harmless partial through the cabin’s outgoing channel without exposing the real slip.

The fake report is signaled across the river while the real danger remains hidden.

Tang remains elsewhere on duty, unaware of the hidden warning, while Lin remains locked inside.

The chapter ends with Lin alone, the fake report sent and the true message hidden on her body.