Trivia

Benedict Cumberbatch claimed that his character of Christopher Tietjen was one of the more admirable he has ever played. He claimed "[Christopher] has many admirable qualities I'd like to siphon off into my life."

The series covers the women's suffrage movement during 1914. Anne-Marie Duff who plays Edith Duchemine, played a dedicated feminist activist in Las Sufragistas (2015)

Reunites Benedict Cumberbatch and Roger Allam, who previously starred together in BBC Radio 4 sitcom Cabin Pressure.

Both Benedict Cumberbatch and Rupert Everett have played Sherlock Holmes- Cumberbatch in Sherlock (2010) and Everett in Sherlock Holmes and the Case of the Silk Stocking (2004).

Rupert Everett's introduction scene in Episode 3 as Mark Teitjens is a scene where the gentleman across from mentions an "Algy Hyde" from the paper and Rupert Everett has previously played Algernon, "Algy", in the Importance of Being Earnest film (2002).