Oswin stands six feet tall, pale and straight-backed, with a handsome, almost stubbornly youthful face. His blond hair lies flat as combed straw beneath a common flat cap. He occupies space carefully, turning his shoulders sideways in doorways and lowering his head as if accustomed to entering a hound's kennel. His blue eyes have a heated, uncanny brightness when he is tired or angry. His cap brim is rubbed nearly smooth at one spot where his thumb worries it. In black hound form he is long-legged and dense-coated, with a muzzle that seems to drink in lamplight.

Kindness comes naturally to him when no one is asking what he is. Under pressure he grows shrewd, evasive, and frighteningly decisive. He is proud of the life he built but still aches for the freedom of his roaming years. With his family he is tender; when he senses danger, tenderness can turn into watchful possessiveness.

Oswin says he was raised among Yorkshire's dales and learned livestock work from his father. The truth is older and less tidy: he wandered the moors and dale roads for years as a Barguest, sometimes guiding the lost, sometimes frightening them, and never staying long enough to become known. He settled into a sheep farmer's life after meeting Mary, whose plain kindness made him want a home instead of another road. He owns a fine house for his station and works hard to deserve it. On their wedding night, after failing to consummate the marriage in human shape, he took his black-hound form and came to Mary as the headless Barguest she feared, its red, saucer-bright eyes the only features she remembers. She struck it with iron scissors. Oswin has never told her the creature was him. Their son William was born with black hair and Oswin's burning blue eyes; the village calls him Black William or Blackby, and Mary fears he is the Barguest's spawn. William is slow to speak and learn, though Oswin patiently spends time with him every day. Mary does not know what Oswin is, and Oswin does not know she confided the wedding-night story to her father, who is increasingly suspicious. Mary's other pregnancies have failed, and Oswin fears he cannot give her a healthy or lasting heir. At certain seasons, when old things stir on the moors, he barely sleeps and dreams of the dales he once roamed.