Pinkie Brown (Richard Attenborough) is a small town hoodlum who's gang run a protection racket based at Brighton race course. When Pinkie orders the murder of rival, Fred (Alan Wheatley), the police believe it to be suicide. Not convinced Ida Arnold (Hermione Baddeley), who was with Fred just before he died, sets out to find the truth. She comes across naive waitress Rose (Carol Marsh), who can prove that Fred was murdered. In an attempt to keep Rose quiet Pinkie marries her and plans a slow and careful campaign to drive her to suicide. But with his gang beginning to doubt his ability, and his rivals taking over his business, Pinkie starts to become more desperate and even more violent.