Rio de Janeiro. In a plush bar, Henry Holland sits talking to another man. Several people - including pillars of the local community - pay their respects. Holland's companion congratulates him on his popularity. Holland begins to tell his story.

London, one year earlier. Holland is responsible for supervising deliveries of gold bullion from the refinery to the Bank of England. He has cultivated a reputation as an unimaginative fusspot, while secretly plotting to one day pull off a spectacular robbery - only one problem remains: how to get the gold out of the country.

At his lodgings at the Balmoral Hotel in Lavender Hill, he meets new tenant Pendlebury, an amateur artist. Miss Evesham, is anxious about all Pendlebury's equipment, until Holland suggests the empty stable.

Holland visits Pendlebury's workshop, where he manufactures cheap tourist memorabilia. Pendlebury shows him the casting room, where he is making gold-painted, solid lead Eiffel Tower paperweights for export to Paris. Holland gets an idea. Back at the stable, he outlines a hypothetical plan for robbing the bank. He suggests the gold could be smuggled to France in the form of 'solid lead' paperweights.

Holland is horrified to be offered a promotion. He is forced to accept, meaning the robbery must take place that Friday. First, however, they need a gang. They devise a plan to attract criminals, but publicly speaking, loudly, about money unattended in Pendlebury's workshop.

That night, they sit and wait for potential robbers. Eventually, the bait works, and they are joined by two thieves, Lackery and Shorty. Satisfied with the pair's credentials, Holland and Pendlebury outline their plan.

The robbery goes almost to plan, except that Pendlebury is arrested after absent-mindedly taking a painting from a market trader. Back at the loading point - a disused warehouse by the river - the others must continue without him. As an alibi, Shorty and Lackery bind and blindfold Holland, then become scared and leave. Holland is spotted by the two security guards, just as he falls into the water.

At the police station, Holland sees Pendlebury, who assumes the game is up and almost confesses before the trader decides to drop all charges and he is released. Later, he tells the others that Holland has been caught. He and Shorty return to the Balmoral to retrieve evidence. Pendlebury is delighted to run into Holland.

News of the robbery is everywhere. Holland is treated as a hero. As the police continue their fruitless search, the paperweights make it past Customs and the gang make plans for Paris. At the last minute Lackery and Shorty decide to stay behind, trusting their colleagues to return with their share of the profits.

Holland and Pendlebury head for Paris to retrieve the gold statues from Pendlebury's assistant, who runs a kiosk at the top of the Eiffel Tower. Due to a misunderstanding, however, she has mistakenly sold six of the gold statues to a party of English schoolgirls.

They return to England, where Holland meets Inspector Talbot, and learns that Pendlebury's van is under suspicion. Later, he visits Pendlebury's workshop, and sees one of the Eiffel Tower statues.

Holland and Pendlebury visit the girls' school in Hendon, where they exchange five gold statues for lead ones. One little girl, however, refuses to swap. They follow her to the Police Training School, where a public exhibition is in progress. She gives the statue to an officer friend. Inspector Talbot sees it and becomes suspicious, giving it to a colleague to test it for gold. Pendlebury grabs it, and the two flee, pursued by dozens of officers. In the confusion, they escape and steal a police radio car.

With other cars in pursuit, they use the radio to put their pursuers off the scent. One collides with a passing car, linking their radio aerials together and broadcasting 'Old Macdonald' across the police network. At a junction, Holland and Pendlebury are forced to give a lift to a constable. As they drop him off, however, the radio is fixed, betraying them. Pendlebury is caught, but Holland gets away with the six gold statues.

Rio. Holland concludes his story. At his companion's suggestion, the two leave - in handcuffs.