Fitz is an addicted gambler, a heavy drinker, and a brilliant, if deeply flawed criminal psychologist. Follow Fitz as he investigates an accused commuter train killer with amnesia, a couple who share love and murder, and the killing of a young boy that shakes a community to its core.

After years of psychiatric healthcare, Ray (Daniel Craig) is deemed fit to be released into the care of his brother and help out in his café. But while his refusal to take medication begins to affect his stability, Ray still manages to strike up a relationship with Laura (Kelly Macdonald), who's impressed by his direct approach to life. Slowly and without the drugs, Ray's grasp on reality begins to slip.