From the No.1 bestselling author of HOW I LOST YOU, which Clare Mackintosh called 'utterly gripping', comes a chilling new novel. Perfect for fans of Louise Jensen's THE SISTER and Katerina Diamond's THE SECRET, Linda Green and Paula Hawkins.Karen is meant to be the one who fixes problems.It's her job, as a psychiatrist - and it's always been her role as a friend.But Jessica is different. She should be the patient, the one that Karen helps.But she knows things about Karen. Her friends, her personal life. Things no patient should know.And Karen is starting to wonder if she should have let her in . . .