The film is based on Christie's book Three Act Tragedy (1934), published in the US under the title Murder in Three Acts. It was Ustinov's third and last portrayal of Poirot on television, and sixth overall including the feature films that preceded the TV movies.
Another screen adaptation in 1988, Appointment with Death, was Ustinov's last portrayal of the Belgian detective.[3]
Plot
Poirot joins his assistant Hastings in Acapulco, Mexico, where Hastings is staying. They go to a party at which the other guests include the writer Janet Crisp, the American actor Charles Cartwright, a clergyman called Babbington, Daisy Eastman and her daughter Egg, Dr Strange, and Ricardo Montoya. Babbington dies of poisoning, then Strange is poisoned, too, and Poirot hunts the murderer.
The main change from the original story is the relocation of the action from London to Acapulco. In the book, Poirot's assistant is Satterthwaite, replacing Hastings, but in the film Hastings is reinstated in his usual role. Christie's English theatrical actor Sir Charles Cartwright turns into Charles Cartwright, an American movie star.
