Series 10, Episode 6 (Spooks)

Section D tries to prevent a terrorist attack from a Russian ultranationalist that will disrupt a partnership between Russia and the United Kingdom, and push both nations into war.

Russian Interior Minister Ilya Gavrik (Jonathan Hyde) arrives in the United Kingdom to propose a strategic partnership between the two nations.

The CIA applies pressure on Home Secretary William Towers (Simon Russell Beale), as they believe Harry to be directly responsible for Coaver's death.

[4] Elena approaches Towers's security advisor Ruth Evershed (Nicola Walker), claiming knowledge of an impending attack, the details of which she will only divulge to Harry Pearce.

Ruth relays this information to her former teammates at Section D. Section chief Erin Watts (Lara Pulver), case officer Dimitri Levendis (Max Brown) and analyst Calum Reed (Geoffrey Streatfeild) decide to illegally break Harry out of CIA custody and escape to an abandoned Ministry of Defence bunker, where they meet with Ruth, Elena and Sasha.

Harry interrogates Elena, who admits she does not know the details, but it has been planned by her handlers, Russian politicians who view their government is becoming too weak, and that a partnership with the UK would be embarrassing.

As Towers meets with the Cabinet Office Briefing Room (COBRA) and sends Eurofighters to intercept the plane, Ruth persuades Harry to make Elena tell him the truth.

Harry is then seen entering the memorial area of Thames House with the names of all the MI5 officers who died in service, some of whom were characters who were killed during the series (Helen Flynn, Danny Hunter, Fiona Carter, Colin Wells, Zafar Younis, Ben Kaplan, Adam Carter, Jo Portman, Ros Myers, Tariq Masood, Ruth Evershed).

They were concerned that there were fans of the show "who will be immensely cheesed off if they get anything less than Ruth riding in on a unicorn to marry Harry in a white suit", but noted there were "plenty of viewers who love the uncompromising toughness of Spooks.

When filming concluded, cast and crew members were "bagsying" items from the Grid set, including a large "Regnum Defende" insignia.

[6] In the week before the broadcast of the episode, the newspaper the Daily Mirror revealed that Matthew Macfadyen would return in a cameo appearance as Tom Quinn.

Susie Boniface of the Daily Mirror called the finale "worth tuning in", stating the series "played a blinder with their swan song".

She said that "there's everything you'd expect - terrorist threats, Harry being quietly furious, Ruth being loyal and a Home Secretary who makes you shout at the telly as Britain comes close to annihilation again", although "sadly it's also got the things I've come to hate in Spooks", citing the "duller-than-a-day-old-sandwich" Dimitri, and "ridiculous lady spook Erin Watts in her four-inch heels".

[13] Jonathan Angwin of CultBox rated the finale five out of five, calling it a "spectacular tour de force of an episode, never before has the ending of a British television programme been so perfectly executed".

Angwin however noted that Elena's false confession was a "terrible move" and did not get the point of Sasha's role despite the actor's strong performance, as he was "impossible to sympathise with" and was "a little irritating".

Despite this the reviewer believed that the terror plot, Elena's interrogation, and the realisation Harry and Ruth would not have a happy ending proved "the final hour of Spooks is easily one of its finest".

[14] Sam Wollaston stated the episode "was like the climax of an indulgent 70s heavy metal track, all banging drums and screaming guitars, licks and twists, and you think that's it, but then there's a bit more, all turned up to 11".

[17] Benji Wilson of The Daily Telegraph rated the episode three and a half out of five, stating "there was so little solid ground to stand on that things started getting a little Electric Kool-Aid", though "normality returned with the death of Ruth".

[19] Caroline Frost in The Huffington Post said "in many respects, Spooks finally did what it has forgotten to do recently, and something it always used to do best [...] deal with an unprecedented random and enormous threat".

[20] Christopher Hootan stated "it was with great trepidation that I sat down to watch the show's finale, which promised to put you so far on the edge of your seat as to find your nose touching the TV screen.

Hootan added "as ever this was suitably peril-ridden with plenty of last minute airstrikes and time-sensitive interrogations, but the real tension lay with the fate of everyone's favourite po-faced head of operations, Harry Pearce".