Alan is a web designer, living in London and married to Lana. But when Lana leaves, abandoning their young son, Alan returns to his native Lancashire with the boy. On his first evening back, he receives a piece of news, a reminder from his own disturbed past. As a kid, Alan witnessed a murder by the reservoir close to his home. The killer's dead, but someone's hounding Alan, leaving suble clues. A murder takes place locally. A second person goes missing. Alan visits an unfamiliar house, only to remember it in detail. Then another murder occurs. Alan has to find the person responsible for the killings, but the killer's already befriended Alan's young and is playing games with them all.