Guest Stars Emily Carey as Mary Conan Doyle Noah Jupe as Kingsley Conan Doyle Blake Harrison as Lyman Biggs James Lance as Barrett Underhill Sebastian Croft as Newsie Dritan Kastrati as Vladimir Patlinov Tereza Srbova as Natalia Kroshenko Tommy McDonnell as Nigel Pennington Mary Healey as Mrs. Blake Dean Forster as Herbert Ogilvie Natasha Sparkes as Sophie Helen Millar as Isobel Underhill Scott Jenkinson as Spring Heel'd Jack Paddy C. Courtney as Gaines Craig Conway as Angus Tuttle
