Super fans of Line of Duty have been putting their armchair sleuthing skills to good use following the release of a tense new trailer. Ahead of the return of the hit crime show, which is filmed in Belfast, BBC One dropped a thrilling teaser clip yesterday to whet viewers’ appetites, revealing plenty of twists and turns, intrigue and suspense. But the one minute, 12-second clip reveals a bit more than just what can be expected from Adrian Dunbar’s Ted Hastings and his anti-corruption unit, AC-12 when series six finally airs on Sunday, March 21. Fellas, try to contain yourselvesâ¦#LineofDuty returns Sunday 21st March, 9pm on @BBCOne and @BBCiPlayer. pic.twitter.com/tuvLHKVAAY— Line of Duty (@Line_of_duty) March 9, 2021