Martin Compston, the Scottish actor best known for playing Detective Sergeant Steve Arnott in the BBC crime drama Line of Duty, has confirmed that the upcoming seventh series will be the final chapter of the show's long-running story. Compston first appeared in the role in 2012 as part of a fictional anti-corruption police unit called AC-12. The series has followed the unit's efforts to root out corruption within the police force, and the final season will bring the narrative full circle. Compston, 42, will reprise his role in the final series alongside longtime co-stars Vicky McClure and Adrian Dunbar. During an appearance on ITV's This Morning, he called the upcoming season "incredible" and praised the scripts as "amazing," with "some amazing returning cast." He described the production as "the hardest one we've had to shoot," noting that the series involved "bigger and longer interview scenes, and a ton of action." Compston emphasized that this series would be the conclusion of the story that began in the first season, with all plot threads coming to a head. Ben Shephard, a presenter on This Morning, had previously speculated that the sixth series would be the finale, as it resolved several mysteries. Compston confirmed this, saying, "Well, this is the end. I think it'd be fair to say that this is the end." While he hinted that something "dramatic" will happen in the final episode, he refused to reveal details to avoid spoilers. Compston praised the scripts as "the strongest we've ever had" and expressed confidence in the cast's ability to deliver a successful final season. The final series will focus on the rebranded Inspectorate of Police Standards, the successor to AC-12, as they take on their most sensitive case yet. The cast includes guest appearances from Scottish actor Robert Carlyle, whom Compston called "the kindest, loveliest, most patient man." Returning cast members include Mark Bonnar, Owen Teale, Perry Fitzpatrick, and Christina Chong, while new additions such as Laura Aikman, Amy Leigh Hickman, Levi Brown, and Tom Weston-Jones will join the cast in roles including detective constables and Detective Inspector Dominic Gough.