Orphans of Chance — Peter Taylor

Detective Sergeant John Niven believed that he had adjusted to being adopted long ago. But a personal crisis makes him wonder about his origins, his career, and his future with his girlfriend Gill. Simultaneously, he is hunting a killer who might well be a fellow policeman, and when Gill becomes inexplicably entangled, Niven sinks deeper into the case. When he identifies a break in the investigation it helps him unravel the killer's purpose and, he believes, the killer's identity. In a final confrontation, it appears the fates have been cruelly mocking him and it seems he really is an orphan of chance.