This is the episode in which Poirot receives his iconic lapel pin from Virginie Farraud. The pin is called A "Tussie Mussie" which means Sweet Posey. It is also called a "Victorian Vase". A fresh flower or nosegay of flowers and herbs can be placed in the top, for sweet smell or to match the color or style of one's suit. Poirot's pin was made by a professional jeweller, New Zealander Gavan Riley. Many say Virginie was Poirot's first true love.
This episodes reveals Chief Inspector Japp's full name as James Harold Japp.
In the flashback scenes of this episode, Poirot appears younger and much slimmer. This effect was achieved by Poirot, the younger policeman, having more hair and allowing David Suchet to forego wearing the padding he usually wore to portray the portly Poirot. The trimmer physique is most evident in scenes where the younger Poirot is wearing a suit rather than the police uniform.
At the Companions' ceremony, on his dress uniform Chief Inspector Japp wears three World War I medals: (viewed from left to right) The 1914 Star (with attached clasp showing the wearer was in actual combat between 5 Aug - 22 Nov 1914); The British War Medal 1914-18; and the Allied Victory Medal. These decorations were known colloquially as "Pip, Squeak and Wilfred."
The filming locations are carefully chosen as some of the finest in Brussels.
However, when Poirot and Japp arrive in "Gare de Bruxelles" - Brussels station, it is actually filmed in Antwerp. Brussels South station, as it would have been for Poirot to arrive from England, has been demolished in the 1950s.
Other locations include the Grand Place (bronze statue of t'Serclaes), the tramway museum in Brussels Woluwe, the Cinquantenaire park and triumphal arch, the St-Jan and St-Stephanuschurch. Furthermore the court scenes were filmed in the Brussels Palais of Justice, which was the biggest built in the 19th century in Europe at the time.