Line of Duty series 6 finale review: H’s identity is finally revealed in frustrating series closer

The sixth series of the show came to a close of Sunday (Picture: BBC/World Productions/Steffan Hill/Geraint Williams)*Warning: This article contains spoilers for Line of Duty series six*When a show is as special as Line of Duty, it can leave its fingerprints on popular culture forever. But when a finale falls as flat as tonight’s did, it can change the way fans think about it for the rest of time.There may yet be another series of Line of Duty announced imminently (whether there should be