Lesley Manville and Tim McMullan return for the third and final installment of the Susan Ryeland series.premieres Sunday, September 6, 2026, 9/8c only on MASTERPIECE on PBS.In, editor Susan Ryeland is pulled into a new literary puzzle when she’s hired to work on a continuation novel in the Atticus Pünd series, penned by a troubled young writer. But when the assignment draws her into another very real murder case, Susan soon finds herself cast as a suspect. Meanwhile, within the world of the novel, the enigmatic detective Atticus Pünd travels to the Isle of Corfu where he becomes embroiled in the murder of Lady Margaret Chalfont.