Sir Redvers and Lady Bertha Brandling are planning to host a jolly weekend at their country house, Brandling Hall. Among the guests are a Cabinet minister and his wife, a Hollywood starlet, a well-known playboy and an old school- Crustie, a famous amateur detective, who is accompanied by her travelling companion. Also making an appearance are a notorious criminal, with his henchman, and the Brandlings’ charlady, who has a penchant for mis-quoting Shakespeare alliterative butler and three flighty maids are tasked with making the guests as comfortable as possible. As the party assembles, a web of tangled relationships is revealed and the atmosphere becomes increasingly fraught, culminating in the murder of
one of the guests.

The police are immediately called and it is not long before the celebrated Inspector Corner of Scotland Yard arrives to try to unravel the mystery, aided by a bumbling member of the local constabulary. Corner and Dame Agatha are soon at loggerheads in trying to sort through a plethora of red herrings and people pretending to be someone else as the Brandlings desperately try to retrieve some order from the wreckage of their jolly weekend. In the climactic final scene, the professional and amateur detectives present their respective solutions and the case is solved.