A retired, celebrated detective now domesticated by marriage unexpectedly admits to a past murder but then identifies the true killer to a younger investigator, igniting a fresh inquiry that unfolds in an affluent household. Tension concentrates on locked doors, domestic servants, a butler’s suite, and small clues such as a lace handkerchief, while suspects among family and guests reveal shifting motives. The plot traces methodical analysis of angles and alibis, the interplay of pride and secrecy, and a gradual unraveling of the crime that resolves motive and method through steady deduction.