London, 1882. When the World's End Investigation Bureau receives an anxious visit from a trio of elderly siblings, Lily Raynor and Felix Wilbraham realise that the Fetterplaces are keeping back the heart of the matter. Ancient bones have been uncovered in their garden, and they believe they know whose they are. But so does someone else. On visiting the old house, they are frustrated by the distressed siblings forbidding an inspection their rose bed. Felix returns by night. . .and discovers that the Fetterplace siblings have good reason for their fear. Unconscious and gravely injured, Felix is brought back to Lily's door by concerned strangers. Fully occupied with trying to save his life, Lily begins to wonder who attacked him, and why. Who is buried in the makeshift grave? Did Felix discover something sinister alongside the bones? Whatever it was, it must be dangerous indeed if keeping it secret requires taking a life. . .