P.C. George Dixon (Warner) a long-serving traditional “copper” who is due to retire shortly, takes a new recruit, Andy Mitchell (Hanley), under his aegis, introducing him to the easy-going night beat. Dixon is a classic Ealing ‘ordinary’ hero, but also anachronistic, unprepared and unable to answer the violence of Tom Riley (Bogarde). Called to the scene of a robbery at a local cinema, Dixon finds himself face-to-face with Riley, a desperate youth armed with a revolver. Dixon initially tries to talk Riley into surrendering the weapon, but Riley panics and fires. Dixon walks to his own death almost uncomprehending. Dixon is taken to hospital, but dies some hours later. The ending is another Ealing quirk, with ordinary decent society, including ‘professional’ criminals used to violence, banding together to track down and catch the murderer, who is trapped in the crowd at White City greyhound track in west London. To Andy Mitchell falls the honour of arresting Riley.

Louis Mazzini’s mother belongs to the aristocratic family D’Ascoyne, but she ran away with an opera singer. Therefore, she and Louis were rejected by the D’Ascoynes. Once adult, Louis decides to avenges his mother and him, by becoming the next Duke of the family. Murdering every potential successor is clearly the safest way to achieve his goal.