Although Agatha Christie's original story took place in the 1950s, the setting is moved to the 1930s for continuity reasons.
The "faggot" that Japp serves Poirot towards the end of the episode is a British dish made from chopped, seasoned, pig offal that is formed into a ball and fried or baked.
The adaptation fails to portray the youth hostel as a multicultural hub for both students and travellers, which is how Christie presented things in the original novel. Understandably, several racially stereotyped characters were removed such as the Indian student Chandra Lal, the Italian servants Geronimo and Maria, the Egyptian student Ahmed Ali, the West African student Akibombo (who is described as having a "black woolly head") and the Jamaican student Elizabeth Johnston (who is given the nickname "Black Bess").
The name of Miss Lemon's sister Mrs Florence Hubbard is a reference to another nursery rhyme: "Old Mother Hubbard."
David Burke (Sir Arthur Stanley), best known as Dr Watson to Jeremy Brett's Sherlock Holmes, has been married to actress Anna Calder-Marshall since 1971. Their son, Tom Burke is also a successful actor. All three family members appear in Poirot episodes; wife, Anna, in After the Funeral (2006) and son, Tom, in The Clocks (2009).