Millionaire business man Benedict Farley, a well known eccentric, consults Poirot about bad dreams he has been having. Mr. Farley has dreamed repeatedly of killing himself. Sadly, he does not follow Poirot's advice. When Farley is found dead, Poirot fails to believe that it is suicide and suspects a murder plot relying on hypnosis.
Lovely young actress Valerie St Clair, engaged to marry Prince Paul of Maurania, is the only witness to the murder of Henry Reedburn, a shady and overbearing producer. Prince Paul appeals to Poirot to save Valerie from police suspicion, and the great detective finds he has a conundrum to ponder on, 'When is a murder not a murder?'
At a London restaurant where he often eats, Poirot notices that another regular customer has diverted from his usual meal. As old Anthony Gascoigne lies dying in Brighton, his estranged twin brother, Henry, falls to his death. A tragic accident, or murder? Poirot begins to see connections and decides the answer to the mystery lies in a blackberry pie.
A Mrs Ernestine Todd, from Clapham, asks Poirot to help her find her cook, Eliza, who has disappeared. Poirot, who aims to accept only really significant cases, is at first insulted by such a trivial request. However, after he sees the contents of the missing cook's trunk, he decides the case could prove to be worthy of his talents.