In 1954 young sailor Harold Guppy (Rupert Graves) returns to England to find his family. Rejected by his brother Maurice's (Les Dennis) wife Iris, he takes up lodgings with Marjorie Beasley (Julie Walters), her one-legged war veteran husband Stanley and their teenage daughter Joyce (Laura Sadler). Marjorie seduces Harold and the two are soon having an affair. Joyce, who sleeps in the same room as her mother and also lusts after Harold, begins blackmailing him, forcing him to spend the night with her in a hotel. As the pressure on Harold by the two women increases, he becomes mentally unstable and violent. Based on an actual murder case from the 1950s, with the names changed.