Stuart Bowman, who plays the blacksmith in this episode, plays Alexandre Bontemps, valet to Louis XIV (Louis XIII and Queen Anne's son) on Versailles.
Marc Warren (Rochefort) & Tom Burke (Athos) also worked together on State of Play (2003) as Dominic Foy & Syd respectively.
Luke Pasqualino (D'Artagnan) & Marc Warren (Rochefort) also worked together on Snatch (2017) as Albert Hill & Bob Fink respectively.