A reclusive peer returns to his ancestral house, marries a celebrated stage performer, and tries to maintain aristocratic form while pursuing scientific interests. A sudden death in the household triggers a criminal investigation that entangles relatives, servants, and stage associates, as uncanny physical likenesses and contradictory evidence produce confusion over identity and motive. The narrative unfolds as a puzzle of duplications, misdirected accusations, hidden connections, and tampered witnesses, with episodes of discovery and revelation that gradually expose how appearances, inheritance, and social proprieties complicate the search for truth.