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