identity, the only time when the identity of the murderer has been changed throughout the series; in the book it is Gustave who is Marrascaud, but in the adaptation it is Alice Cunningham (who is changed not to be Rossakoff's daughter-in-law, but a biological daughter), with Gustave being her accomplice, along with Dr Lutz. The adaptation marks the second and final appearance of Countess Vera Rossakoff in this series, played here by Orla Brady. The previous appearance was broadcast in 1991, in the episode "The Double Clue", where Kika Markham played Rossakoff. Filming for this episode took place in April and May 2013 and was directed by Andy Wilson, who also directed Death on the Nile and Taken at the Flood for the series. Wilson described this adaptation as "a journey of restoration and redemption for Poirot". The location in this adaptation, a Swiss hotel called "Hotel Olympos", was shot in Halton House in Aylesbury; however, the bedrooms were built at Pinewood studios. Publication history 1947: Dodd Mead and Company (New York), 1947, Hardback, 265 pp 1947: Collins Crime Club (London), September 1947, Hardback, 256 pp 1951: Dell Books, Paperback, 255 pp 1953: Penguin Books, Paperback, (Penguin number 928), 254 pp 1961: Fontana Books (Imprint of HarperCollins), Paperback, 256 pp 1967: Greenway edition of collected works (William Collins), Hardcover, 319 pp 1967: Greenway edition of collected works (Dodd Mead), Hardcover, 319 pp 1978: Ulverscroft Large-print Edition, Hardcover, 467 pp; First publication of stories All of the stories except for "The Capture of Cerberus" were first published in the UK in the Strand Magazine with illustrations by Ernest Ratcliff as follows: "The Nemean Lion": November 1939 – issue 587 "The Lernaean Hydra": December 1939 – issue 588 "The Arcadian Deer": January 1940 – issue 589 "The Erymanthian Boar": February 1940 – issue 590 "The Augean Stables": March 1940 – issue 591 "The Stymphalean Birds": April 1940 – issue 592 "The Cretan Bull": May 1940 – issue 593 "The Horses of Diomedes": June 1940 – issue 594 "The Girdle of Hippolyta": July 1940 – issue 595 "The Flock of Geryon": August 1940 – issue 596 "The Apples of the Hesperides": September 1940 – 597 "The Capture of Cerberus" was rejected by Strand Magazine and was not published as part of the series. A new story under the same title first appeared in the Collins first edition. The original story surfaced in 2009