Mary is a Yorkshire woman with wheat-blonde hair usually pinned beneath a kerchief and clear blue eyes that seem to keep watch even when she is smiling. Her cheeks are wind-reddened, her skin roughened by cold water, lye, and years of outdoor work. She moves with a practical, economical stride, shoulders slightly forward as if forever carrying a basket. When unsettled, she draws breath through her nose in three sharp, audible catches. The unexpected thing is that she can imitate the piping call of a curlew with uncanny accuracy, a trick she learned as a child and still uses to amuse herself while working.

Mary is tender with people in distress but impatient with those who confuse comfort with truth. In a busy household she is brisk, teasing, and capable; when alone after sunset, she becomes watchful and methodical. She longs to trust Oswin's calm explanations, yet resents being hurried toward them. Her courage is not fearlessness: it is the decision to keep asking questions while frightened.

Mary grew up in a stone hamlet in Yorkshire, daughter of a sheep shearer and a woman who knew the practical uses of every plant on the slope. She met Oswin Hirst at market, where he quietly repaired the handle of her mother's basket instead of trying to impress her. She loves his steadiness, though his habit of searching every strange occurrence for a sensible explanation sometimes leaves her feeling alone with what she saw. On their wedding night, Mary woke to a presence beside the bed. She remembers a cold pressure at her shoulder, the smell of wet earth, and a shape that seemed to bend the room around it. She could not cry out. At dawn, the wedding linens were damp though the windows had been latched. Oswin found her shaking and stayed with her until she could speak. He believes exhaustion, fear, and a badly secured shutter explain it. Mary wants to believe him, but cannot forget the sense that the presence knew her name. Since then, she has helped keep their household running while quietly asking shepherds and midwives whether anyone else has seen a figure near the old boundary stones. She has begun sleeping with a lamp lit, which strains their closeness and their dwindling supply of oil. She still loves Oswin and does not want fear to make a stranger of her, but she needs him to take her memory seriously.