Episode 10

It starts as a birthday. Fiona's birthday, marked with what should be a routine look at a possible terrorist safe house. The safe house is supposed to be empty; it is not. Birthdays and safe houses don't usually appear in the same sentence, which is the point. Then Fiona, Danny and the rest of the team are taken.

Adam Carter is handed the kind of choice that would break anyone. Wesley Carter, played by James Dicker, is Adam's son, which puts the choice in the cruellest possible frame: with his son, his wife and Danny in the hands of the kidnappers, Adam has to decide who doesn't walk away. The prime minister's life is on the table too, which gives MI5 a government-sized headache on top of a personal one. The demands come with a deadline, because they always do, and the clock runs through the whole hour. The kidnappers want something from the government, and the government's answer is never as simple as the demand. And then Danny Hunter makes the call himself.

Raza Jaffrey's Zafar Younis, Mido Hamada's Butterfly, Paul Jesson's Guy Facer and Rob Dixon's Mike give the episode its threat and its texture. Every one of them gets a moment, which is how you make an ensemble death land. Shauna Macdonald's Sam Buxton and Rory MacGregor's Colin Wells hold the office together. Peter Firth is Harry, running the crisis from the centre. Rupert Penry-Jones's Adam is the man with the impossible decision. Ben Richards and David Wolstencroft wrote it; Alrick Riley directed.

Series three ends here, and it ends hard. Danny's exit lands because the show earned it: the team had louder personalities, but Danny was the one you believed. The aftermath scenes are the hardest, and the show doesn't rush them. The episode doesn't let anyone off lightly, least of all the audience. It's a finale that respects what it's taking away. It's the rare finale that earns its silence.