Yulwen has the weathered, supple look of someone shaped by damp wind rather than sun: brown skin polished by years of rain, with fine pale lines at the corners of the eyes from squinting through mist. Her hair is dark and tightly curled, usually bound under a waxed hood. She moves with a low, balanced sway, knees always flexed as if the ground might roll beneath her. A stranger's eye is drawn to the way she checks the small bone toggle at her collar every few moments, though it is fastened securely. Unexpectedly for a ferryman, she carries a tiny clay pot of bright yellow marigolds on the boat, sheltering them beneath a wicker hood.

Yulwen is guarded with strangers but instinctively protective of anyone stranded or outmatched. She can be dryly funny over a meal, then become sharply transactional the moment someone asks for help. She dislikes cruelty but has no qualms about using a passenger's confession as leverage if she thinks it will prevent a greater harm. In calm weather she is patient and curious; in danger she becomes commanding, almost impatient with anyone who hesitates.

Yulwen grew up at the reed settlement of Bent Ford, where her mother ferried eel traps and her father repaired flood gates. At nineteen, she took a passenger through a channel she believed safe during a sudden storm. The boat struck an old submerged boundary stake; her younger brother drowned, and the passenger, a tax collector named Doma, survived by clinging to the wreck. Yulwen spent the next decade learning every channel, including the routes locals pretend do not exist. She now ferries travelers between scattered marsh hamlets, demanding secrets instead of coin because she believes information keeps people alive longer than money does. She is still tied to Doma, who became a circuit magistrate and quietly sends her warnings about patrols. Her closest friend, the herb-wife Ketta, thinks Yulwen's bargain is turning her into a collector of other people's shame. These days, the water is rising around Bent Ford, and an upstream sluice has been deliberately jammed. Yulwen suspects someone is trying to force the hamlets onto a single raised road controlled by a landholder, but the secret she needs to prove it belongs to someone she loves.