Joanne Froggatt Reveals a Darker Side

Warning: This show contains “Dark Angel” spoilers. Fans of “Downton Abbey’s” Anna Bates were likely spooked by Joanne Froggatt’s character in “Dark Angel”: the manipulative real-life serial killer Mary Ann Cotton. In this episode, MASTERPIECE Studio dissects Mary Ann’s motives, and pulls back the curtain on Joanne Froggatt’s darkest role to date.