The BBC and BritBox have expanded the cast of "Hercule," a six-part series exploring a young Hercule Poirot, adding Jack Gleeson and James Nesbitt alongside previously confirmed lead Edward Bluemel. The show, described as "an intimate study of Hercule Poirot the man, and an epic portrait of Britain between the wars," marks a significant new addition to the Agatha Christie adaptation landscape and is due to begin filming imminently in Liverpool.

Further cast joining the production include Henry Ashton, James D'Arcy, Calvin Demba, Phil Dunning, Tamsin Greig, Guy Remmers, Rebecca Rittenhouse and Mawaan Rizwan. The series will draw on three of Christie's early stories while introducing Poirot to future allies and a key nemesis, with scripts by Benji Walters and directing duties split between Jonny Campbell, Chanya Button and Alrick Riley. Produced by Mammoth Screen and Agatha Christie Limited, it will air on BBC iPlayer and BBC One in the UK, with a BritBox release in North America planned for 2027.