The third and supposedly final installment of Anthony Horowitz’s mystery series, “Marble Hall Murders,” is set to premiere on PBS, streaming on the PBS app, pbs.org, and Cascade PBS (KCTS 9) starting Sunday, September 6, 2026, with new episodes airing Sundays at 9/8c. This series, an adaptation of Horowitz's novel, continues the unique format of intertwining a present-day murder investigation by book editor Susan Ryeland (Lesley Manville) with a Golden Age mystery solved by fictional detective Atticus Pünd (Tim McMullan). The show is part of the Masterpiece series, following the critically acclaimed “Magpie Murders” (2022) and “Moonflower Murders” (2024).
In “Marble Hall Murders,” Susan Ryeland, now a freelance editor in London, is hired to work on a continuation novel titled “Pünd’s Last Case” by Eliot Crace (Jamie Blackley), the troubled grandson of a legendary children's author (Patricia Hodge). This job unexpectedly embroils Susan in a new murder investigation, leading her to become a suspect. Simultaneously, within the fictional novel, Atticus Pünd travels to Corfu, Greece, where he becomes involved in the mysterious death of a British matriarch (also played by Patricia Hodge) and faces his own mortality, assisted by a local police officer (Zubin Varla) and an Albanian police lieutenant, Achilles Vassilikos. The narrative elegantly dances between these two timeframes, highlighting parallels and occasionally overlapping elements, with double-casting often providing subtle hints.
The series is praised for its top-notch acting, including Lesley Manville’s portrayal of Susan, Tim McMullan’s Pünd, Patricia Hodge’s elegant hauteur, and Danny Sapani’s D.I. Blakeney. Production took place in Dublin, Corfu, and London, reflecting the story's split locations. Anthony Horowitz and executive producer Jill Green have framed “Marble Hall Murders” as the conclusion to the Susan Ryeland trilogy, with Horowitz noting that Manville’s enthusiasm for another installment was the catalyst for him writing this third book. Viewers can watch “Magpie Murders” and “Moonflower Murders” on PBS Passport before the new series.
