Episode 1

The train is nearly at Euston when the trouble starts. David Budd, a police sergeant with a military past he does not advertise, stops a suicide bomber on his way to London Euston. The aftermath is odd even by police standards: the hero of the hour is arrested and interrogated alongside the two terrorists. He does get promoted out of it. Budd is moved onto close protection and handed the Home Secretary, Julia Montague, as his principal.

The fit is wrong from the first meeting. Montague backed Iraq and Afghanistan and wants to update RIPA, which her critics read as a quiet attack on civil liberties. Budd came home from the wars hostile to all of it. Her ex-husband Roger Penhaligon, the Chief Whip, suspects she is using the terrorist threat to position herself to replace the Prime Minister. But Budd is not much steadier at home, where PTSD and a failing marriage to Vicky are taking turns to break him. A meeting with Andy Apsted, an old army friend at the Veterans Peace Group, does not help; Apsted is plainly disgusted by the uniform his friend now wears.

Jed Mercurio wrote it and Thomas Vincent directed, and the casting does the work. Richard Madden had spent his Game of Thrones years being killed off young and nobly; here he gets to be noble and survive, mostly. The part won him a Golden Globe, and Marvel would come calling later. Keeley Hawes gives Montague the armour and the calculation the part needs, with Sophie Rundle's Vicky, Pippa Haywood's Craddock, Paul Ready's Rob MacDonald, Nicholas Gleaves's Penhaligon, Tom Brooke's Apsted, Vincent Franklin's Travis and Matt Stokoe's Luke Aikens around them.

It is a pleasure to watch a political thriller open with danger this physical. The stakes are personal and professional from the first ten minutes, and the show knows it.