Guest Stars Emily Carey as Mary Conan Doyle Diana Quick as Cecelia Weiss Noah Jupe as Kingsley Conan Doyle Louise Delamere as Louisa "Touie" Conan Doyle Jerry-Jane Pears as Florrie Penny Downie as Mrs. Sulzbach Simone Kirby as Sister Grace Adelayo Adedayo as Sister Winnie Amanda Lawrence as Sister Mathilda Patrick Galligan as Beale Eileen O'Brien as Sister Fabian Flora Turner as Lucy Allthorpe