Mrs. Wilberforce is a charming, eccentric old lady who lives with her parrots in a small house near King's Cross Station in London. Professor Marcus is very taken with the location of the house and rents two rooms from Mrs. Wilberforce. Under the pretext of making music together, Professor Marcus begins meeting with his friends Major Courtney, Harry, Louis, and "Pancake" at Mrs. Wilberforce's house. The lovable old lady thus gets to enjoy classical string music to her heart's content and marvels at how beautifully the professor and his friends can play. Mrs. Wilberforce has no idea that she has actually fallen prey to a gang of scoundrels who are using a record player to fool her so they can prepare a sophisticated money robbery in peace. Only when "Pancake" has a mishap while hastily making his escape with the loot does Mrs. Wilberforce realize what is going on. This could have serious consequences for her, but luckily the gang cannot agree on who should get rid of the quirky old lady. Alexander Mackendrick tells the imaginative and original story of five gangsters, each one funnier than the last, who may appear tough but are completely overwhelmed by the lively, talkative Mrs. Wilberforce, who is constantly serving tea. This makes the challenge of deciding who should eliminate the old lady all the greater.