Guest Stars Adeel Akhtar as Inspector Lestrade Susie Wokoma as Edith Grayston Fiona Shaw as Miss Harrison Ellie Haddington as Miss Gregory Frances de la Tour as The Dowager Hattie Morahan as Lady Tewkesbury Claire Rushbrook as Mrs. Lane Burn Gorman as Linthorn David Bamber as Sir Whimbrel Tewkesbury
