Oswin stands exactly six feet tall, his pale, youthful face framed by straight flax-blond hair that lies flat as wet straw beneath a common flat cap. His blue eyes are startlingly bright, almost fever-blue when the hound nature presses close. His skin is pale with a wind-roughened, ruddy cast across the nose and cheeks. He waits with his weight on the balls of his feet, as if ready to cross a field in one bound, and his broad, callused hands keep drifting to his thighs as though checking for fur. His clothes smell faintly of lanolin, rain, and turned earth. The incongruity people notice within minutes is that he keeps a tiny, neatly folded paper dancing card tucked into his cap, a relic of his former wandering life.

Oswin is gentle in daily life but not soft: he can comfort a frightened lamb with exquisite patience and drive a cheating trader into the mud with the same steady composure. He is practical and shrewd, yet sentimental about his roving years. Around Mary he tries to be reassuring, but guilt makes him evasive; around William he is openly tender, though any hint of danger makes him abruptly feral. In safe company he can be wry and almost boyish. During uncanny seasons he becomes watchful, sleepless, and hard to reach.

Oswin says he was born in the Yorkshire dales and spent his youth roaming between farms, fairs, and lonely roads. He speaks of that life as though it ended only a decade ago, though older villagers remember a blond traveler with his face appearing in stories from their grandparents' time. He took up sheep farming, acquired a fine stone house for a man of his station, and married Mary, hoping routine and affection could quiet the old wildness. On their wedding night, his first attempt to consummate the marriage in human form failed under fear and unfamiliar tenderness. He shifted into the headless black Barguest shape Mary feared from local tales, its red, saucer-bright eyes the only features on its neckless head. Mary struck the beast with iron scissors after the act. Oswin remembers the blow, but more vividly remembers the intimacy of being trusted enough to remain beside her until dawn. He has never told her that the creature was him. Mary believes a Barguest assaulted her and fathered William, their slow-to-speak son, whose black hair and burning blue eyes have made locals call him Black William or Blackby. Oswin loves them both and spends every possible hour at home, especially during the uncanny seasons when he cannot sleep. Mary's other pregnancies have ended in loss, and her father has begun quietly investigating Oswin. Oswin still dreams of the dales as they were before he settled, and fears that his own nature, or whatever runs in William's blood, will eventually make the house unsafe.