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, one by one.
Before they die, each victim is given a small white book...
For months, detectives have failed to catch Billy, or work out what the white books mean. And then a woman, scared by what she's seen on the news, comes forward.
Stand-up comedian Kim Tribbeck has one of Billy's peculiar little books. A stranger gave it to her at a gig she did 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?
This is the next chilling novel from the queen of psychological crime - a literary puzzle set to unlock the dark side of the mind . . .
Sophie Hannah is an internationally bestselling crime fiction writer. Her crime novels have been translated into 34 languages and published in 51 countries. Her psychological thriller The Carrier won the Specsavers National Book Award for Crime Thriller of the Year in 2013. In 2014 and 2016, Sophie published The Monogram Murders and Closed Casket, the first new Hercule Poirot mysteries since Agatha Christie's death, both of which were national and international bestsellers. Sophie's novels The Point of Rescue and The Other Half Lives have been adapted for television as Case Sensitive, starring Olivia Williams and Darren Boyd. Sophie is also a bestselling poet who has been shortlisted for the TS Eliot award. Her poetry is studied at GCSE and A-level throughout the UK. Sophie is an Honorary Fellow of Lucy Cavendish College, Cambridge. She lives in Cambridge with her husband, two children and dog.