Hours after his sister's wedding, a restless Ian Rutledge drives aimlessly, haunted by the past, and narrowly misses a motorcar stopped in the middle of a desolate road. Standing beside the vehicle is a woman with blood on her hands and a dead man at her feet. She swears she didn't kill Stephen Wentworth. A stranger stepped out in front of their motorcar, and without warning, fired a single shot before vanishing into the night. But there is no trace of him. And the shaken woman insists it all happened so quickly, she never saw the man's face. Although he is a witness after the fact, Rutledge persuades the Yard to give him the inquiry, since he's on the scene. But is he seeking justice - or fleeing painful memories in London?