WARNING: This episode contains spoilers for Moonflower Murders Episode 5. Actor Mark Gatiss is a familiar face in the MASTERPIECE world. From Sherlock to Wolf Hall to Nolly, he always brings a unique charm to his characters and scripts. Today, we talk with Mark about playing timid film producer Oscar Berlin and prickly Frank Parris in Anthony Horowitz’s Moonflower Murders, as well as his love of golden age murder mysteries.