Michael Weston
Harry Houdini
Stephen Mangan
Arthur Conan Doyle
Rebecca Liddiard
Constable Adelaide Stratton
Emily Carey
Mary Conan Doyle
Noah Jupe
Kingsley Conan Doyle
Diana Quick
Cecilia Weiss
Adam Nagaitis
Sergeant George Gudgett
Tim McInnerny
Chief Inspector Horace Merring
Jacob Blair
Benjamin Graves
Bo Martynowska
Young Woman (as Bo Martyn)
Paddy C Courtney
Mr. Gaines
Louise Delamere
Touie Doyle
Jerry-Jane Pears
Florrie
Edward Akrout
Henry
Patrick Carney Junior
Upper Class Gent
Lady Conny Sharples
Amanda Posh (as Conny Sharp)
Tereza Srbova
Natalie
James Lance
Barrett Underhill
Simone Kirby
Sister Grace
Mary Healey
Mrs. Blake
Andrew Bicknell
Exorcist
James Fleet
Dr. Pilsen
Andrea Lowe
Beatrice Upton
Jeremy Swift
Dr. Henry Whitaker
Owen Teale
Professor Havensling
Emily Hampshire
Madame Korzha
Nathan Stewart-Jarrett
Elias Downey
Enuka Okuma
Jane Downey
Angela Curran
Vera Stuffts
Esh Alladi
Dr. Kasad
Gillian Saker
Rosie Berry
Tom Canton
Paul Hargreaves
Sarah Abbott
Libby Cotter
Lara Jean Chorostecki
Clara Reid
Billy MacLellan
Constable Billy McKinnon
Peter Outerbridge
Thomas Edison
Adelayo Adedayo
Winnie
Penny Downie
Mrs. Sulzbach
Philip Gascoyne
Scotland Yard Detective
Amanda Lawrence
Sister Mathilda