Series 10, Episode 6 (Spooks)

The episode sees the conclusion of the "Tourmeline"^{[clarification needed]} story arc for series ten. Russian Interior Minister Ilya Gavrik (Jonathan Hyde) arrives in the United Kingdom to propose a strategic partnership between the two nations. Gavrik's wife, Elena (Alice Krige), was a former MI5 spy codenamed "Tourmeline" run by Harry Pearce (Peter Firth). Harry and Elena were lovers in the early 1980s, and Harry believes that Sasha Gavrik is his son. While the talks take place, MI5 uncovers a number of attempts to derail the agreement: An attempt made on Gavrik's life,^[1] MI5 analyst Tariq Masood (Shazad Latif) is killed after discovering the identity of the person who reactivated Elena,^[2] and an assassin attempts to shoot Elena.^[3]

Harry becomes convinced that Jim Coaver (William Hope), deputy director of the Central Intelligence Agency (CIA) and Harry's partner during 1982, is responsible for the attacks.^[3] Harry abducts and interrogates Coaver, who denies any knowledge of the attacks. Coaver is surrendered to a group posing as CIA personnel, who drive away with him moments before the actual CIA officers arrive. When the MI5 team realise their mistake, they give chase. Coaver is pushed out of the rear of the speeding van during the pursuit and subsequently dies on the street. The CIA applies pressure on Home Secretary William Towers (Simon Russell Beale), as they believe Harry to be directly responsible for Coaver's death. They demand Harry be handed over to CIA custody for extradition to the United States. Harry urgently requests that Towers bring the signing of the agreement forward as quickly as possible.^[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. However, he is scheduled for immediate deportation to the United States. 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. However Elena does recall a telephone number, leading Dimitri and Erin to an address. There they find a picture of a man in a jammed paper shredder. Elena recognises the man as Pavel Zykov (Andrew Byron), a Russian ultranationalist.

Zykov is on board a flight from Moscow bound for London. It is believed he will carry out a suicide mission by exploding the plane over London. Such an action may push Russia and the UK into war. Using a device smuggled onto the aircraft, Zykov jams all communications from the plane, and with no other choice Harry and Towers decide to shoot down the plane before it can reach UK airspace, where debris could cause civilian casualties on the ground. However Ruth suspects Elena is lying about the bomb. In further interrogations Elena admits that during the time Harry ran her in the 1980s, she was already working for the KGB, and in fact recruited Harry without him knowing it by making him fall in love with her, and by falsely claiming that Sasha is his son.

Ruth becomes convinced Elena wants the plane to be shot down, since it is a Russian airline flight full of civilians, and a British air strike upon it would infuriate the Russian government, ending the partnership negotiations. 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 resorts to threatening to kill Sasha in order to gauge her reaction. It becomes clear that Elena is willing to sacrifice her son to complete her mission. Convinced it was her plan to force the shooting down of the passenger plane, Henry instructs Towers to abort the mission, however Towers is not convinced. Harry solicits the help of Gavrik, who agrees but only on the condition that he be put in the same room as Elena. When this is granted, Gavrik threatens Towers with military action against the UK unless the attack is aborted. With seconds to spare, Towers complies, averting disaster. The plane goes on to land safely at Heathrow Airport with Zykov arrested.

After confronting his wife, Gavrik locks the door and strangles Elena to death. Sasha is unable to stop it. Meanwhile, Ruth joins Harry outside the bunker, and they both decide to leave the intelligence service and live together. However Sasha, armed with a large piece of broken glass and blaming Harry for his mother's death, tries to stab him. Ruth intervenes and is stabbed instead. She dies from her injuries before help can arrive, leaving Harry to mourn the loss of his love. In a telephone conversation with Towers sometime later, it is evident that Harry is considering leaving the service. It also becomes clear that Harry has engaged an outside agency to assassinate Mikhail Levrov (Jeffry Wickham) and his co-conspirators. Towers requests he not be informed of the details of these actions. Tom Quinn (Matthew Macfadyen) is shown walking into Levrov's house for an appointment with him. 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). He then walks onto the Grid, sits down at his desk and answers the phone, indicating he intends to continue working in the service.

During the writing stage of the tenth series, lead writers Jonathan Brackley and Sam Vincent knew of the strong possibility it was going to be the last series, so the two were looking for ways to infuse their scripts with a sense of finality. When the decision to end the show was made definite by Kudos Film and Television, the production company behind Spooks, Brackley and Vincents were given enough time to plot a true conclusion to the show. They stated "by the time we began to write the final ep, we knew it would be the last".^[5]

They also felt that writing the final episodes of a popular programme was "an exciting responsibility, a daunting honour". They also did not want to end it on a cliffhanger, as doing so wouldn't be right or fair to the fans. The writers also concluded the Ruth/Harry arc in the series. 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. And both viewpoints were always well represented around the table". When it came to writing the final scenes, both writers went through "countless" ideas, some of which were pondered for weeks before making their final decision. In an interview, both writers admitted that the finale "can't please everyone", but that they tried to create an ending that was faithful to the spirit 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. Tom was the head of Section D in the first two series and then was decommissioned from MI5 in series three, after which he started a private security firm. A series insider said that the character would only be seen "fleetingly" in the episode. The insider also said "It will bring back all the memories of Tom and what the character endured in those first few series." However, at the time it was not revealed why the character returns^[7]