Who is mad? Who is sane? Who decides? Welcome to the Dorothy Fish, a hospital in North London. N has been a patient for thirteen years. Day after day, she sits smoking in the common room and swapping medication. Like the other patients, N s ambition is never to be discharged. Then, in walks Poppy Shakespeare in a short skirt and snakeskin heels. Poppy is certain she isn’t mentally ill and desperate to return to her life outside and, though baffled, N agrees to help her. But in a world where everything’s upside down, are they crazy enough to upset the system?