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 Sian Brooke as Eurus Holmes Simon Kunz as Sir Edwin Wanda Ventham as Mrs Holmes Timothy Carlton as Mr. Holmes Indica Watson as Little Eurus Clare Foster as Velma Ralph Ineson as Vince Brett Allen as Special Unit Guard Paul Weller as The Viking Art Malik as Prison Governor Aaron Richards as Young Mycroft Honor Kneafsey as Girl on Plane Richard Crehan as Ben Tam Mutu as Leonard Rhys Rusbatch as Technician Tom Stoughton as Young Sherlock Harry Tuffin as Victor Trevor Matt Young as Young Police Officer
