A suspenseful mystery begins when a nocturnal visitor appears in a hospital ward, touching off inquiries that disturb comfortable assumptions. Investigations move from clinical rooms to family homes and an old house on a hill, revealing hidden relationships, ambiguous deaths, and contested documents. The narrative alternates close observation of illness with social maneuvering and legal and moral dilemmas as several participants assemble clues and confront obligations. Resolution hinges on a decisive choice that clarifies questions of identity, motive, and consequence.