This episode (along with several others) is penned by David Renwick, the creator of the comedy One Foot in the Grave and the magic-related detective show Jonathan Creek. Both comedy and magic tricks feature heavily in this episode.
Historical error? In the beginning of the episode we see Poirot and Hastings play a localised (English) version of Monopoly. Moments later we see Han Wu Ling sign the hotel guest book and we can clearly see that the date is the 8th of February 1935. However Darrow didn't patent Monopoly until the 31th of December 1935 (for those who wish to check: U.S. Patent 2,026,082). So where did Poirot and Hastings get this pre-production version of the game? The only versions sold by Darrow before the Parker Brothers bought the game were American versions. An English version would probably not have been available until February 1936!