Mo Xi looks as if he has been pressed flat between the house's rules and its weather: narrow shoulders, straight back, and careful, economical steps that make almost no sound on bare boards. His skin has the warm, matte look of old teak; his close-cropped hair is threaded with grey and lies like soft wire. He smells distinctly of clove soap, boiled linen, and the faint mineral damp of a cellar. He knows about the soap, but not the cellar scent. His front teeth are worn smooth from years of holding pins and thread while mending; when he laughs, which is rare, he covers his mouth with the back of one hand. The unexpected detail is the little paper boat he folds from every discarded guest receipt, setting each one afloat in the washbasin before bed.

Mo Xi is courteous without being warm and observant without being intrusive. In ordinary moments he is patient, almost ceremonious; when someone is hurt or a room is threatened, he becomes startlingly decisive. He dislikes being thanked for routine work, yet quietly remembers every kindness done for him. He trusts evidence, but behaves as though the house knows things he cannot prove.

Mo Xi was raised above a riverside laundry, where he learned that clean sheets could soothe a fever, conceal a bruise, or hide the fact that someone had never come home. At twenty, he took work as a porter at the guest house locals call Old Wash, a name left over from the drainage crews who cleared the marsh before its foundations were laid. During a flood, a stairwell collapsed and trapped three lodgers below. Mo Xi heard a fourth voice behind a bricked-up wall, though no one else did. He broke the wall open and found only a narrow chamber, dry as bone, with a child's handprint in its dust. The experience changed him: he stopped treating a house as a container and began treating it as a witness. The owners later hired him as steward, but never explained the building's former purpose. He has served there for nineteen years, keeping it immaculate and sleeping in a narrow room off the scullery. He exchanges letters with his elder sister, Fen, who wants him to retire and come live near her family. The current owner, Mrs. Dava, is selling the property to a developer who intends to gut its oldest rooms. Mo Xi has begun quietly delaying the surveyors, though he has no legal claim to the house and no clear idea what he hopes to save.