Agatha Christie’s Poirot. Anne Hart

target="_blank" rel="nofollow" href="#ulink_3ad5f5e2-93ac-5322-b40c-ffe01241d5aa">8 In the 1920s, and always to his great astonishment, Mr Satterthwaite had been the associate of another of Agatha Christie’s detectives, the mysterious Harley Quin.

9 Also published under the title Death in the Air.

10 Before coming to work for Poirot, Miss Lemon served as secretary to yet another of Agatha Christie’s detectives, Parker Pyne.

11 Also published under the title Poirot Loses a Client.

12 Though a much longer case, Miss Arundell’s posthumous summoning of Poirot is reminiscent of Miss Barrowby’s in ‘How Does Your Garden Grow?’.

13 Two others published during this period, ‘The Incredible Theft’ and ‘Dead Man’s Mirror’, are expanded versions of ‘The Submarine Plans’ and ‘The Second Gong’.

14 Also published, sometimes in slightly differing versions, under the titles ‘Crime in Cabin 66’, ‘The Mystery of the Crime in Cabin 66’, and ‘Poirot and the Crime in Cabin 66’.

15 During this voyage a fellow passenger asked Poirot if he had ever been to Egypt. ‘Never, Mademoiselle,’ he replied, completely forgetting ‘The Adventure of The Egyptian Tomb’ of the 1920s, a remarkable lapse of Poirot’s famous memory that I can only ascribe to seasickness.

16 Although Cards on the Table was published in 1936, a sobering remark by one of its characters – ‘Even if somebody did push their great-aunt down the stairs in 1912, it won’t be much use to us in 1937’ – places events of this case in the following year.

17 Like Poirot himself, Superintendent Battle, Ariadne Oliver and Colonel Race each has his or her own separate sphere in Christie literature. To bring the four of them together at his dinner table was certainly a triumph for Mr Shaitana.

18 This book should not be confused with a Parker Pyne short story of the same title.

19 Also published under the titles Murder for Christmas and A Holiday for Murder.

20 Also published under the titles The Patriotic Murders and An Overdose of Death.