Returning to England after years of police service abroad, Luke Fitzwilliam shares a train compartment with a talkative elderly woman bound for Scotland Yard. She confides that her quiet village has lost several residents to apparent accidents and illnesses, and that she alone recognizes the pattern of a killer who is about to strike again. Luke humours her until he reads, days later, that she was struck down by a hit-and-run car before reaching London, and that the man she named as the next likely victim has also died. Unable to dismiss the coincidence, he travels to Wychwood under Ashe under a borrowed pretext and begins quietly studying the people who knew the dead. Among them are a self-made peer who dominates the village, his sharp and watchful secretary, the local doctor and his junior partner, a blustering retired major, a solicitor, and an observant spinster. Each death looks innocent on its own, yet the accumulation suggests a patient hand selecting victims for reasons Luke cannot yet trace. As he draws closer to the truth, he realizes that the killer has noticed his interest and that the next accident may be arranged for him. The narrative weaves detection through ordinary village life, where motive hides behind manners and any neighbour might be capable of murder. It is a standalone puzzle that turns on small observations and the unsettling ease with which a careful person can kill and be believed.