Alec Guinness plays criminal mastermind Professor Marcus in The Ladykillers (1955).
Marcus leads a gang that rents a room from the elderly Mrs. Wilberforce, pretending that the men are musicians. They use the house as a base for planning and carrying out a cash robbery. Their elaborate disguise begins to unravel when Mrs. Wilberforce discovers the truth.
Alexander Mackendrick directed the film for Ealing Studios. Its humor comes from the contrast between the gang's criminal ambitions and the respectable, old-fashioned world surrounding their landlady. Guinness's performance became one of the best-known examples of his comic work.
The film is sometimes confused with the 2004 Coen brothers remake, which moved the story to the American South and starred Tom Hanks. Guinness's Professor Marcus belongs specifically to the 1955 British original.