The opening music is 'Kiss a dream', from the album 'Swingers & Crooners' (2008) by Marquee All Stars Big Band.
At the reading of Mrs Llewellyn-Smythe's Will, one of the shots of those present is clearly mirrored. This appears in a brief wide view of four of the characters sitting in the reverse order from the order in which they appear in the rest of the scene.
This story was also adapted as a television film in 1986 under the alternate title Murder in Three Acts, with Peter Ustinov reprising his role as Hercule Poirot.
Poirot travels to and from Monte Carlo on board The Blue Train, the main setting for the earlier episode The Mystery of the Blue Train.