Music professor Alec Guinness rents a London flat from sweet old lady Katie Johnson. He tells her that, from time to time, several other musicians will visit in order to rehearse.
In truth, Guinness can't play a note, nor can his visitors: he's a criminal mastermind, holding court over a gang of thieves, including the likes of punkish Peter Sellers, homicidal Herbert Lom and punchdrunk Danny Green. The gang uses Guinness' flat as headquarters as they conceive a daring 60,000 pound robbery.
After pulling off the job, the gang stuffs the loot in a railway station locker. To avoid detection, Guinness convinces the ever-trusting Johnson to pick up the money. Through a series of comic complications, Johnson returns home with a police escort, with neither the woman nor the bobbies suspecting that she's carrying a fortune in her suitcase.
Mistakenly believing that Johnson has ratted on them, the gang reluctantly plans to eliminate her. The Ladykillers won an Oscar nomination for William Rose's screenplay, and a BFA award for veteran character actress Johnson.