Season 4 of the BBC’s hit drama, written and created by Jed Mercurio, returns on March 26, and this time with a new face leading the chase for a serial killer – DCI Roz Huntley, played by Thandie Newton.

The series begins with DCI Huntley and her team in the thick of a career-defining case, Operation Trapdoor. Under intense pressure to catch the culprit and prove herself to her superiors, and facing conflict with her colleague, Forensic Coordinator Tim Ifield (Jason Watkins), it’s not long before AC-12 decide to probe her handling of the investigation. A mother of two and wife to husband Nick (Lee Ingleby), Roz will do anything to stop her life unraveling. Anything.

Creator, writer and Executive Producer Jed Mercurio says: “Thanks so much to the fans who’ve made ‘Line of Duty’ such a success. Thanks to the BBC for all their support in making the series. It’s incredibly flattering we’ve been able to attract such amazing talent as Thandie Newton, Jason Watkins and Lee Ingleby to join our brilliant regular cast of Martin Compston, Vicky McClure and Adrian Dunbar. We’re all looking forward to tormenting the nation with ever more diabolical plot twists!”

The award-winning series moved to BBC One after its huge success since launching on BBC Two in 2012. This third season was the highest-rating BBC Two drama series ever since current measuring system began in 2002, with a series consolidated average of 5.1 million. The exhilarating 90-minute finale consolidated at 5.6 million.

Produced by Cait Collins, the executive producers are Jed Mercurio and Simon Heath for World Productions, and Stephen Wright for BBC Northern Ireland. With support from Northern Ireland Screen.

“Line of Duty” premieres on BBC One on March 26. For those in the USA, previous seasons of the series (Lenny James, who plays Morgan on “The Walking Dead” starred in season 1) are available on Hulu to stream. So the upcoming 4th season will likely make it to Hulu as well… eventually.

Watch a trailer for the upcoming season below: