A body in a locked room. A house full of secrets. And a nineteen-year-old woman who sees what the police cannot.

When Frederick Wyndham is found dead in the ice house of his family's Oxfordshire estate, stabbed and sealed inside a room with one door and no way out, the police are baffled. The case goes cold.

Nell Blackwood arrives at Braeburn Hall posing as a library assessor. Secretly guided by Roderick Fane, a reclusive detective confined to a wheelchair in his crumbling North Oxford study, she must unpick the household's tangled loyalties, buried affairs, and a fraud that has been hiding in plain sight.