Unforgotten on Masterpiece

PBS | 9:00 pm

Nicola Walker and Sanjeev Bhaskar return to their roles as Detective Chief Inspector Cassie Stuart and Detective Inspector Sunny Khan as this hit mystery series returns for Season 4, after a third season that pulled in the show's highest ratings during its run to date. The creative team has yet to release much story information for the new season, but speaking broadly, writer and executive producer Chris Lang says it's about the relationship between civilians and the police. "I'd say it's both a love letter and (an accusation)," he suggests.