Jorren is a compact halfling with weather-browned skin roughened by wind and fine silt. His shoulders pitch forward from years bent over maps, but his steps are quick and precisely placed, as if the ground were a page he is reluctant to smudge. Ink stains run from his fingertips into the creases of his palms. A cracked brass surveyor's compass hangs at his chest; its leather cord is polished almost smooth where his thumb worries it. The unexpected thing about him is the little paper windmill pinned to his cap, replaced whenever rain destroys it.

Jorren is cautious with a map and impulsive when a person is in immediate danger. He distrusts grand plans but is sentimental about small, practical kindnesses. In calm company he is wry and patient; under pressure he becomes brisk, exacting, and unwilling to soften a warning.

Jorren grew up in Silt's Warning, where the river shifts its channels and yesterday's road can become a mudflat by dawn. His mother, Poma, ran a ferry crossing; his father, Tavi, repaired millstones. As a child, Jorren learned to read current lines from his mother and to measure distances by the rhythm of his father's turning wheel. During the flood known locally as the Long Thaw, a levee gave way while Jorren was guiding a supply cart. He chose what looked like the shortest route, and the cart bogged down. His older cousin, Nima, stayed behind to free it and was swept away. Jorren survived, but the event changed his belief that a good map merely showed the way: it must also tell people when not to go. Now he surveys roads, flood paths, and dry-season wells, recording each revision on scraps of flour sack because proper paper is scarce. He shares information with ferry crews and farmers, but clashes with settlement reeve Olo, who wants a straight road through land Jorren considers unsafe. Jorren still sends a portion of his pay to Nima's daughter, Sumi, who lives upriver and believes her father may yet return.