Country squire Marcus Waverly calls on Poirot for help in dealing with kidnap threats against his son. Hastings is appalled by the thought of someone going around kidnapping children and it becomes a race against time to find the identity of the mystery letter writer.

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.

Poirot is on holiday at the Palace Hotel, Rhodes, when an Englishwoman, Mrs Valentine Chantry, is poisoned. Poirot unravels several complicated relationships between those staying at the Palace Hotel.

Poirot and Hastings are on board a ship steaming towards Alexandria. Poirot recovers from his usual sea-sickness to take an interest in some fellow passengers, especially the Clappertons. On arrival at Alexandria, Mrs Clapperton is found murdered in her cabin.

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?'

Poirot and Hastings take a holiday in Cornwall, looking for peace and quiet. They meet Miss Nick Buckley, who lives near their hotel at End House, and she tells Poirot she has had three near-fatal accidents in a few weeks. He then finds a bullet hole in her hat, returns with her to End House and is drawn into a complex murder investigation.....

Poirot is summoned to Marsdon by the owner of a country inn there to solve a murder. But the inn-keeper is a would-be thriller writer, and to Poirot's dismay the murder turns out to be fictional. Thankfully, though, there is soon a real (if seemingly supernatural) murder at the big house. Things get even more interesting when a young wife claims that a tree in her garden is haunted by a laughing ghost, and there are also signs of black magic from East Africa. Poirot lays a clever ambush to smoke out the killer,confident that he or she will turn out to be human.

Poirot attends the Victory Ball, a costume party where you are expected to dress as someone famous, as himself. However, when two members of a party of six dressed as characters from classical Italian comedy are subsequently found dead, Poirot finds himself working with Chief Inspector Japp to solve the case. The solution to the deaths of Viscount Cronshaw and Coco Courtney is to be found in determining the correct time of death and identifying an impostor at the ball. Poirot takes to the airwaves and reveals the identity of the killer on a live BBC radio broadcast.

Hercule Poirot accompanies his friend Captain Hastings on a weekend shooting party at the home of Harrington Pace, but he isn't having a very good time. He comes down with the flu and takes to his bed but when Pace is shot dead in his study, he rises to the occasion to assist Inspector Japp in solving the case.