MI-5: Volume 10

A fiery farewell! Never shown on television, the final season of the hugely successful, long-running BBC drama reaches a thrilling conclusion in six riveting hour-long episodes. The crack counter-terrorism unit of the British Secret Service tries desperately to mend relations in the US and Middle East, while the squad tracks down a known anarchist who may be building a dirty bomb in London.

Episode 1 - Two months following the death of Lucas North, and after trading Albany, a state secret, for Ruth Evershed (Nicola Walker), Sir Harry Pearce (Peter Firth) is on garden leave until a tribunal can determine his future with MI5. With help from Home Secretary William Towers (Simon Russell Beale), Harry returns to work on a provisional basis until the tribunal's conclusion. Harry learns that old friend Max Witt (Giles Havergal) was murdered. His Russian opposite, Ilya Gavrik (Jonathan Hyde), is smuggled into the country by Towers, who reveals Gavrik is proposing a partnership between Russia and the United Kingdom without the Americans knowing. It has emerged that Witt was killed because he knew somebody is posing as Harry using his old coded messages from the Cold War; the imposter made contact with Elena (Alice Krige), Gavrik's wife, and Harry's former asset. Section D learns of a kill order by the Chechens on Gavrik during a function. Harry intercepts the assassin, who flees and then killed by new Section D Chief Erin Watts (Lara Pulver). Despite this, the assassin's handlers deem the mission a success. Harry meets with Elena, and tells her they should meet again at a safe location. Later, Harry reveals to Ruth that he and Elena were lovers, and that FSB officer Sasha Gavrik (Tom Weston-Jones) is their son.

Episode 2 - On his way to MI6, Calum Reed (Geoffrey Streatfeild) is mugged, and his laptop containing the identities of five high level assets is stolen, one of which is Martha Ford (Lydia Leonard), who is close to one of Gavrik's companies. Several attempts to find the muggers prove difficult as they are highly resourceful. They manage to decrypt the first file and leak it to the Internet; asset one John Grogen is found dead. Martha's identity is leaked next, though Erin is able to bring her to a safe house before she can be killed by the Russians. However, Erin is later ordered to break all ties with her under the pressure from Gavrik. Harry meets with Elena to tell her that somebody is posing as him. He later asks Ruth to look up Central Intelligence Agency (CIA) deputy director and Cold War colleague Jim Coaver (William Hope), believing he is the imposter. After returning home Tariq Masood (Shazad Latif) discovers the identity of one of the muggers. However, he realises they are on to him, and tries to get the intel to Thames House. Before he can get there though, a man poisons him by injection, and dies as he arrives to meet Calum.

Episode 3 - Trace amounts of radioactive material has been found at Heathrow Airport. Section D find that known anarchist Johnny Grier (Mel Raido) is in the city, who is believed to be making a dirty bomb in London. To get to him, Dimitri Levendis (Max Brown) is assigned to honeytrap his sister, Natalie (Georgina Rich), via Internet dating. Section D follows him to a cell, who plans to attack the Velanon Group, a financial company who made millions from a nuclear disaster. When Dimitri confronts him, Grier reveals he thought he was smuggling heroin to the country, and is not part of the bomb plot. Reluctantly he agrees to help; they find a van, only to find it empty; Grier double crossed them. He intends to assassinate Velanon's CEO using the radioactive powder. Dimitri fails to stop him, and the building is evacuated. Meanwhile, Towers offers Ruth a promotion as his security advisor. Harry's suspicion into Coaver has been solidified, especially after Calum found what Tariq found before his death; one of the muggers was also present during Gavrik's assassination attempt. Furthermore she is a CIA asset.

Episode 4 - When the parole of a controversial religious leader is turned down, he appoints two recently released inmates to commit a revenge suicide mission. One of the inmates, Ashur, is an asset from the prison who passed on information to MI5. Ashur agrees to help them stop the attack on the condition that his daughter be given British citizenship. However, the bombers decide to kidnap her as well as Erin's daughter to ensure the attack succeeds.

Episode 5 - Harry kidnaps Coaver, believing him to have set up the recent attacks against Gavrik and MI5. This comes with consequences as the CIA are now coming after Harry. After realising Coaver was possibly not responsible, they and Ruth must steal his laptop from the US embassy to find who is.

Episode 6 -Harry has been arrested on suspicion of the death of the CIA's deputy director, but the officers of Section D break him out of custody. Elena Gavrik informs Harry of a plot to attack the UK.

Directed by Alrick Riley, Julian Holmes and Bharat Nalluri
Written by Sam Vincent and Jonathan Brackley, Sean Cook, Anthony Neilson
Produced by Chris Fry
Executive Produced by Jane Featherstone, Simon Crawford Collins, Howard Burch