David Walker, a toy manufacturer, usually made it a rule not to give lifts to stray young women. And on this occasion, with his business preoccupations and anxieties about his wife, most hitch-hikers would have forgiven him for passing them by.

But this one was an extremely pretty girl in her early twenties, wearing a set of fairly new jeans and with a cheeky cap on her head; there was something innocent and appealing about her. Her face fell as she saw that he intended to ignore her signals and as he gathered speed he was left with the impression of an almost despairing disappointment. He relented at once.

It was the biggest mistake of his life. When she disappears, David is caught in a sudden storm of intrigue and confusion; the picture may have been blurred, but the frame was set. And somewhere in the picture are blackmail, big money, and murder. Detective Inspector Martin Denson has only the faintest of outlines from which to discover the truth. And he has less time to do it in that he thought.