Guest Stars Rupert Graves as DI Lestrade Una Stubbs as Mrs. Hudson Louise Brealey as Molly Hooper Mark Gatiss as Mycroft Holmes Andrew Scott as Jim Moriarty Amanda Abbington as Mary Morstan Simon Kunz as Sir Edwin Sian Brooke as Eurus Holmes Timothy Carlton as Mr. Holmes Wanda Ventham as Mrs Holmes Ralph Ineson as Vince Brett Allen as Special Unit Guard Art Malik as Prison Governor Rhys Rusbatch as Technician Aaron Richards as Young Mycroft Indica Watson as Little Eurus Clare Foster as Velma Richard Crehan as Ben Honor Kneafsey as Girl on Plane Paul Weller as The Viking Tam Mutu as Leonard Tom Stoughton as Young Sherlock Harry Tuffin as Victor Trevor Matt Young as Young Police Officer
