Guest Stars David Morrissey as John Arbuthnot Hugh Bonneville as Edward Masterman Barbara Hershey as Caroline Hubbard Eileen Atkins as Princess Dragomiroff Marie-Josée Croze as Greta Ohlsson Jessica Chastain as Mary Debenham Brian J. Smith as Hector MacQueen Toby Jones as Samuel Ratchett Samuel West as Dr. Constantine Sam Crane as Lt. Blanchflower Denis Ménochet as Pierre Michel Serge Hazanavicius as Xavier Bouc Tristan Shepherd as Lt. Morris Susanne Lothar as Hildegarde Schmidt