Episode 7

Iran now has full nuclear capability, and the diplomacy is desperate. Harry Pearce and Bob Hogan persuade Ana Bakhshi to go on live television and announce that Iran is ending its uranium enrichment programme. It is meant to be the peace accord moment, broadcast to the world, and the broadcast is the only thing keeping the deal alive; everyone knows it. Then armed activists learn the truth and hijack the signal, and the announcement turns into a siege with the whole world watching through a stolen camera.

Adam Carter and Ros Myers are on the ground, tasked with defusing the situation before somebody gets hurt. They have to work out who is in the studio and how far the hijackers will go, all while the signal stays live and the world watches their mistakes in real time. There is a particular nastiness to the idea: the peace deal itself is what gets held to ransom.

David Farr and David Wolstencroft wrote it, Stefan Schwartz directed. Rupert Penry-Jones plays Adam Carter, Hermione Norris plays Ros Myers, Agni Scott plays Ana Bakhshi and Peter Firth plays Harry Pearce. Miranda Raison's Jo Portman, Mark Bazeley's Paul Mills, Alex Lanipekun's Ben Kaplan, David Yelland's Stephen Castledine, Angela Bruce's Ruth Chambers and Matthew Marsh's Bob Hogan make up the supporting cast.

But the hour works because the stakes are public and the clock is a camera. Everyone is performing for it, from the politicians to the gunmen, and the people holding the weapons understand that better than anyone else in the room. Nobody in the building is telling the whole truth, and the broadcast is just the most public liar.

It is a nasty, clever little thriller, and it does not let the audience off the hook either. We are watching a broadcast about the end of a crisis while the crisis happens behind the broadcast, and the episode is happy to leave you sitting with that.