Episode 6

Catherine's final shift, and the scores are settled for good. The series ends the way it began, with Catherine Cawood doing the job and paying the price for it, and the finale lets the valley's long story run its course. George Costigan's Nevison Gallagher is back, which feels right for a closing chapter: the man whose daughter's kidnapping set all of this in motion, still standing in the same valley.

Ryan faces a moral dilemma, and Rhys Connah carries it without overplaying. The boy has grown up in this role, from the eight-year-old at the teacher's meeting to a young man with a decision that would flatten most adults. The finale gives him the weight to hold his own scenes.

The supporting cast files in for the last round: Susan Lynch's Alison Garrs, Oliver Huntingdon's Ivan Sertic, Jack Bandeira's Matija Jankovic, Laura Castle's DC Harding, Siobhan Finneran's Clare, Con O'Neill's Neil Ackroyd and Vincent Franklin's Andy Shepherd.

The dilemma at the heart of the finale is not a puzzle with a clean solution. It is the kind of choice that changes the person who makes it, whichever way they go. Ryan has spent three series watching the adults around him carry their decisions. Now the decision is his, and the episode gives him the space to make it feel real rather than staged.

After three series of violence and grief, the show ends on something closer to relief than triumph. That is the honest ending. The valley will still be there in the morning, with all its secrets and its ordinary people, and Catherine has done what she could with it.

Sally Wainwright wrote it, Fergus O'Brien directed. It is a satisfying close for long-running characters, even if the endings leave questions hanging about what comes next. Catherine gets a conclusion that fits her: earned and unglamorous. For a show this good at endings, that's the right way to go out.