Benson (Kenneth Williams) and Potter (Leslie Phillips) patrol their beat

      A flu epidemic sweeps Britain, affecting every industry, including the police force. With constables dropping like flies, raw recruits just out of training school are thrown into the thick of the action, as well as the incorrigible Timothy Gorse, a special constable whose services are only called upon as a last resort.

      Before long, the new faces, except for the efficient WPC Passworthy, are causing chaos wherever they tread. After coming to the assistance of a distraught mother who thinks she’s lost her little boy, Gorse decides to play around on the boy’s scooter, only to find himself bumping into PC Benson, who’s out walking Lady, a police dog. As they crash down some steps, the dog runs off.

      Benson regards himself as an expert in the physiology of the criminal mind, claiming he can spot a crook a mile off. When a man bumps into him in the street, Benson doesn’t regard the man as anything but a law-abiding member of the public, that is until his trousers fall to the ground because the passer-by has stolen his braces. Another example of his ineptness sees him trying to persuade a supposed car thief from committing a crime, only to discover that embarrassingly he’s accusing a detective sergeant from the CID.

      With the threat of suspension hanging over their heads, the new recruits pound their beats in pairs. Potter and Benson spot the getaway car involved in a recent robbery, and identifying a way of redeeming themselves for the earlier fiascos, try and find the robbers themselves. Eventually assisted by Gorse, they manage to catch the crooks in an abandoned house but it’s the lazy, inefficient Inspector Mills who takes all the credit and is transferred to an area college where, ironically, he’ll be in charge of morale and discipline, with Sergeant Wilkins taking over the running of the station after his long-overdue promotion to inspector.