William is a small, solemn child with soft cheeks and a watchful stillness that makes adults lower their voices around him. His skin has a warm brown cast, usually smudged with flour or hearth soot. He moves in careful, delayed starts, as if each step must first be considered; when startled, he goes utterly still. In a room, his eyes keep returning to the hearth, even when it is cold. The unexpected detail is that he hoards smooth, clean buttons and arranges them in careful circles, a patient little ritual wholly at odds with the fearful name locals have given him.

Cautious with strangers but curious about small, harmless things; easily overwhelmed yet stubborn about keeping his buttons in order. He is quiet in crowds and surprisingly playful with Oswin, especially when shown a familiar toy. When frightened he withdraws, but when he feels safe he tries to share whatever has caught his attention.

William is the young son of Oswin Hirst, born in a room above the old kiln at Fourth Sieve, a settlement built around grain milling. He was a quiet infant, and his speech and movement have developed more slowly than other children’s. Oswin has met every worried milestone with patience, teaching him one small task at a time, though tenderness has never quite eased the dread with which Oswin watches the strange soot patterns that sometimes appear around William. During a winter chimney fire, William was found asleep in his cot while the room filled with smoke; the soot around him had formed a neat ring, and the flames had bent away from the bed. Since then, neighbors have called him Black William, or Blackby, sometimes affectionately and sometimes as a warning. Oswin’s widowed sister, Odelia, brings William little carved animals and insists he is simply a child who needs time. Their nearest neighbor, Pavo, has begun telling people the boy is an omen, hoping to drive Oswin from a disputed cottage. William’s present problems are ordinary and urgent: he tires easily, dislikes unfamiliar hands, and needs adults who will protect him without treating him as a mystery to solve.