The second page of the The Strand newspaper, issue December 2nd, 1894, has a drawing of Inspector Jacques Clouseau from the Pink Panther series. Specifically, the image is taken from the theatrical poster for the 1982 film Trail of the Pink Panther.

In the scene of Sherlock and Watson on the train departing from Switzerland, a young boy named Hercule approaches Sherlock to help solve his puzzle box and the boy's mother appearing named Madame Poirot. This is a reference to the fictional detective Hercule Poirot by author Agatha Christie, alluding to the young boy being the character.

On the left hand of the NPC Champagne, a tattoo can be seen of the logo for Frogwares, the game's developer.