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