What if having a best friend was the most dangerous thing you could do? A killer that the police are calling 'Billy Dead Mates' is murdering pairs of best friends. Before they die, each victim is given a small white book... For months, detectives have failed to catch Billy but then a scared woman comes forward. Kim Tribbeck has one of Billy's peculiar little books. A stranger gave it to her a year ago. Was he Billy, and does he want to kill her? Kim has no friends and trusts no one, so how, and why, could she possibly be Billy Dead Mates' next target?