The patients make up a wide spectrum including Roy, a manic-depressive with a passion for theatre; Cherry, who has a food obsession and is a Lewis-addicted romantic; Ruth, suffering from obsessive–compulsive disorder (OCD) and is shown as obsessed with counting and distinguishing between illusions and reality; Doug, a pyromaniac, who loves sexual innuendo; Julie, dependent on drugs in the outside world; Henry, an older, silent man, previously a lawyer; and Zac, a drugged-up pianist.
Other characters include Justin, a social worker at the mental institution; Lewis's girlfriend Lucy and his best mate Nick, whose strongly left-wing ideals Lewis has followed up until now without question. Meeting patients with views different from Lucy's and Nick's opens Lewis' eyes to other people and the world around him, teaching him to be more tolerant.
