Episode 7

A Pakistani intelligence officer is shot dead in South London, and the murder lands on Section D with both feet. The head of the Pakistani service comes to Harry and Ros with more than condolences: there is a planned attack coming, aimed at Muslim communities, and the people behind it are Hindu nationalists. Stop the attack, and stop the war it would start. The enemy here is momentum, and that is harder to fight than a man with a grudge.

The episode becomes a race to find the where and the when, with the temperature of two communities rising by the hour. Ruth and the rest work the leads while the clock does its work, and the show does not pretend the politics are tidy. There is a real dread in the way the hour handles it, the sense that the attack itself might not be the worst thing that gets set off.

James Dormer and David Wolstencroft wrote it, and Edward Hall directed. Peter Firth's Harry and Hermione Norris's Ros carry the departmental side, with Nicola Walker's Ruth on the intelligence and Richard Armitage's Lucas in the field. Sagar Arya plays Victor Chatterjee, Ashley Kumar is Ashok Veerkal, Phaldut Sharma is Harish Dhillon, Harmage Singh Kalirai is Hamid Ahmed, Imran Mirza is the Pakistani Intelligence Officer, and Tobias Menzies turns up as Andrew Lawrence. It is a crowded cast, and every face earns its place.

But Spooks rarely goes this close to home, and the hour is stronger for it. The threat is domestic, and every street corner carries a weight you do not get from a foreign plot. It leaves you with the uncomfortable thought that stopping one attack and stopping a war are two different jobs. The hour trusts the subject matter, and the subject matter rewards the trust.