Jessa has a broad, weather-browned face and a compact frame that seems built to brace against a crowded doorway. She walks with her weight slightly forward, favoring her left side when turning, as if perpetually making room for someone behind her. A small brass thimble hangs from a cord at her belt, polished bright on one rim and dark with age inside. Her presence gives the impression of a person who has learned to notice exits, hands, and the exact moment a conversation turns dangerous.

Jessa is observant and generous, but not serene: she can be briskly brave when someone else is in danger and evasive when her own feelings are involved. With strangers she is practical and guarded; with children she becomes warm and absurdly patient. When tired, her carefulness curdles into suspicion, and she may treat a delayed answer as proof of a lie.

Jessa grew up with her sister Thessa above a candle-maker's shop, where their mother, Nerys, rented a narrow room and took in mending to keep the household afloat. Their mother taught both girls to read by having them sort scraps of correspondence customers left in coat pockets. Jessa became fascinated by the lives hidden in ordinary letters, while Thessa learned to judge people by what they did rather than what they wrote. Years ago, when a fever swept their quarter, Jessa spent a night carrying messages between isolated households. She found a child alone beside a dead letter-carrier and chose to deliver the carrier's last bundle before seeking help. The delay still weighs on her, though the child survived. Their mother died recently and left the sisters a rented room and a box of letters they have not yet managed to sort together. Jessa has been paying the rent from copywork and errands, while the landlady, Oona, has given them until the next market week to decide what to do with the room. Several letters bear marks from a district that officially stopped receiving mail years ago.