Detective Peter Porteous has been called to Cranwell Lake, where the body of a teenager has been discovered. After trawling through missing persons files, he deduces that the corpse is Michael Grey, an enigmatic and secretive eighteen-year-old reported missing in 1972. Prison librarian Hannah Morton is about to get the shock of her life. For Michael was her boyfriend, and she was with him the night he disappeared. The news report that his body has been found brings back dreaded and long-buried memories from her past and begins a deadly chain of events.