Three people with extreme obsessive compulsive disorders (OCDs) agree to live together as part of a ground-breaking experiment in an attempt to cure them through a new kind of group therapy. Wendy Johnstone hasn’t shared a bed with her husband or even touched her twin children for five years, confining herself to one room in her home which no one is allowed to enter. Gerard McAree is terrified of any human contact for fear he might incriminate himself. He can’t leave phone messages, refuses to write anything down and walks around in public with a mouthful of water to stop himself from talking. Sophie Prosser Morgan spends three hours a day washing her hands and can’t bring herself to walk on grass.

Over the past 20 years, all three have tried medication, assorted therapies and even contemplated lobotomy in order to rid themselves of their OCDs. In this last ditch attempt at salvation, they agree to share a house in London and put themselves in the hands of a team of therapists from the Psychiatric Unit of London’s Maudsley Hospital. Wendy, Gerard and Sophie’s journey to overcome the debilitating effects of their illness proves more intense and surprising than anyone, including their doctors, could ever have imagined.