Alec Guinness portrays a mild-mannered criminal mastermind in The Lavender Hill Mob, an excellent British caper comedy.
Our film opens in Rio de Janeiro, where Henry Holland (Alec Guinness) is a popular man, renowned for his elaborate parties and generosity. He's at a cafe telling a guy about his humble origins and how he came into his money. A year previously, he had been a meek bank clerk in London, living an unremarkable life in a simple boarding house, and reading gangster stories to his elderly co-tenant Mrs. Chalk (Marjorie Fielding). His main job at the bank was supervising the transfer of gold bullion, a job he'd been doing for twenty years, driving everyone nuts with his fastidiousness and paranoia. It turns out that was exactly the persona he was trying to sell - the entire time, he was after a way to steal the bullion himself and smuggle it abroad. The only thing stopping him was not being able to come up with a way to smuggle it out of the country. That changed when his boarding house got a new tenant - an artist named Alfred Pendlebury (Stanley Holloway) who made and sold souvenirs for tourist shops around the world - gold-painted miniature Eiffel Towers, for instance. Holland took Pendlebury into his confidence and talked him into helping with the heist. They also tricked a pair of burglars (Sidney James and Alfie Bass) into helping with the robbery and getaway (I won't give away how, despite the spoiler warning - just trust me that it's clever). Despite an occasional snag and some comedy of errors moments, the heist was successful, earning them one million pounds. In a beautiful bit of irony, Holland (who played hostage as his alibi) was lauded by the bank and the press as a hero. However, a string of mishaps afterwards endangered not only their earnings, but their freedom as well.