Episode 1

Series seven starts with a British soldier kidnapped by al-Qaeda, and the team steps in. But the real story is waiting back at home. An old protégé of Harry Pearce's has returned after eight years in a Russian prison, and the question hanging over the hour is whose side Lucas North is actually on. Nobody comes back from eight years in Russian custody the same person, and the episode never lets you forget it.

That question follows him into every scene. Harry wants to trust him, wants to believe the eight years changed nothing. The episode is careful to give you reasons to doubt both possibilities, and Lucas himself gives nothing away, which is the point of him. Every handshake with him reads as an assessment, on both sides. His re-integration is the real mission of the hour, and it is a delicate one. Meanwhile the kidnapped soldier has to be found, and the rescue runs in the background, competently, while the character drama does the real work.

Neil Cross and Ben Richards wrote it, Colm McCarthy directed. Peter Firth plays Harry Pearce, Richard Armitage plays Lucas North, and Rupert Penry-Jones's Adam Carter, Hermione Norris's Ros Myers and Miranda Raison's Jo Portman are around them. Alex Lanipekun's Ben Kaplan, Hugh Simon's Malcolm Wynn-Jones, Gemma Jones's Connie James, James Dicker's Wesley Carter and Gus Gallagher's Boscard complete the cast.

It is a good opening because it understands what it is doing. The kidnapping is the hook, but the season is going to be about Lucas, and the hour knows it. Watching Harry put his trust in a man who has spent eight years in the dark is going to cost him. The only question is how much, and the show is in no hurry to answer it. Armitage gives Lucas a stillness that could mean anything, which is exactly the right performance. The soldier's rescue is handled with the brisk professionalism the show reserves for its B-plots, which is not a complaint.