A small child with a broad, watchful forehead and a solemn face that seems to be listening even when he is looking elsewhere. His dense hair grows in a glossy black cap, so dark it throws blue highlights in lamplight, and stands up in soft, stubborn whorls after sleep. He walks with his toes turned slightly inward and keeps his weight poised on the balls of his feet, as if the floor might change its mind. When waiting, he rocks forward and back without seeming to notice. People remember the contrast between that restless balance and his patient, grave stare.

William is curious but easily overloaded: he will study a moth for several minutes, then cover his ears when a door slams. He is affectionate with familiar people yet wary of sudden attention. He wants to please adults, but resists being hurried and may become stubbornly silent when pressured. On calm days he is gently mischievous; when frightened, he becomes watchful and still.

William is the young son of Oswin Hirst and a mother who measures every new word and step against the children next door. His thick black hair appeared at birth, startling a family whose hair is usually pale brown, and locals began calling him Black William, or Blackby, before he could answer to his own name. He was slow to sit, slow to speak, and still struggles to follow quick instructions. His mother fears illness or a lasting developmental difficulty and quietly seeks every healer she can afford. Oswin worries for a different reason: when William was a toddler, a winter fever left him sleeping through a night in which the house's hearth went cold, yet the room stayed warm around his cradle. Since then, Oswin has watched the boy's hair and the fire rather than asking what William might need. A village healer advised patience, plain routines, and no frightening tests. William's current troubles are less dramatic but no less real: the miller's children imitate his careful speech, his mother is exhausted, and Oswin has begun keeping him away from the old kiln where the family once worked. William remembers the kiln as a place that hummed when nobody else could hear it.