A flu epidemic forces a police sergeant to take on four bumbling newcomers.

Due to a flu epidemic which leaves a British police station in dire need of replacements, three police rookies are given a chance to show their mettle. They are: Tom Potter, an ex-playboy and would-be Don Juan; Stanley Benson, a snobbish intellectual with his own views on criminology; and Charlie Constable, a superstitious amateur astrologer. Assisted by effeminate Special Officer Timothy Gorse, the trio bungle every attempt at maintaining law and order. They inadvertently help thieves escape with their loot; Gorse gets caught in midair on a bell tower rope while chasing a cat; Potter investigates a noise and bursts in upon pretty Sally Barry while she is in her bath; Benson arrests a plain-clothes policeman because he looks like the "criminal type"; and Gorse and Benson are arrested when they impersonate women in a disastrous effort to catch shoplifters. Despite all this, the rookies miraculously manage to apprehend a gang of crooks who have robbed an armored payroll truck. Because of their heroic deed, their two astounded superiors, Inspector Mills and Sergeant Wilkins, are given promotions.