Holmes' theory about the brain being like an attic is taken from the original stories by Arthur Conan Doyle.
Ken Marks has played four different characters over the course of the series:
- Episode 3.8 End of Watch (2014) - Moderator
- Episode 2.21 The Man with the Twisted Lip (2014) - Meeting Leader
- Episode 2.7 The Marchioness (2013) - Chairman
- Episode 1.2 While You Were Sleeping (2012) - Moderator