Six months following "The School" it is revealed Jo Portman played dead and then killed her captor Boscard. Private Andy Sullivan is kidnapped by an Al-Qaeda cell, who demand Remembrance Sunday be cancelled or Sullivan will be executed. Harry Pearce finally secures the release of Lucas North, an MI5 officer who was imprisoned in Russia for eight years. He and Adam Carter work together to rescue Sullivan. Meanwhile, Ros Myers is stationed in Moscow and learns that a Chechen assassin codenamed "Tr
Harry asks his superior, Richard Dolby, to pursue Katchimov, but is denied. However, Harry pursues him anyway. Malcolm Wynn-Jones believes there is a Russian submarine in British waters, and deduces its intention to carry out a cyber attack via a submarine communications cable. Lucas meanwhile is revealed to be a double agent for the Russians and is being handled by Elizabeta Starkova, his ex-wife who works in the FSB. After learning of his involvement, Ros brings Lucas in; Lucas claims he is ac
Ben Kaplan is on his first undercover assignment to infiltrate an Al-Qaeda cell that plans to launch suicide attacks after making threats on the Internet. There is to be a dry run first. During the operation, Ben becomes close to fellow cell member Jawad. Later, Ben learns the attacks have been moved forward to take place during the dry run. MI5 and CO19 disarm three of the bombs, and a fourth detonates with no civilian casualties. Section D discover that the "Mr. Big" behind the operation is th
Section D are stunned to learn that Mohammed Khordad, Al-Qaeda's number three, wants to talk with MI5, with intelligence on a planned attack in London in exchange that two Guantanamo Bay prisoners be released and have Home Secretary Nicholas Blake announce this on live television. When this is carried out, however, Khordad is arrested by a CIA team, much to Harry's frustration. After getting him released, Khordad discloses the location of the planned attack; a restaurant. However, Lucas learns f
Ros goes undercover to stop Alexis Meynell, who is trying to bankrupt the United Kingdom. He starts by ruining rival bank Highland Life. As the case unfolds the chairman of Highland Life commits suicide after it is revealed the bank owes £65 billion pounds to Salma, a Russian bank with Russian mafia connections. Meynell's right hand man, Asa Darlek wants the £65 billion paid back, or he will release a statement letting the country know the full extent of its debts. Ros presents a third
Lucas has to protect Dean Mitchell, a teenager in possession of a prototypical weapon that is capable of shutting down all electrical systems in a vehicle. Dean admits he witnessed somebody using the gun to assassinate a paparazzo and then stole it and a backpack. Furthermore, the team that are after Dean are MI6 led by Michael Sands. The paparazzo unknowingly took pictures of a meeting between Sands and UN diplomat Claude Denizet, where Denizet was threatened to resign from peace talks between
Moments after realising he has been framed and before being arrested, Harry phones Lucas and instructs him to meet Sugarhorse asset Maria Korachevsky in Moscow, who should know who the mole is. Harry is tortured to divulge the names of his Sugarhorse assets; if he tells the names, the mole will relay them to the FSB and they will be killed, preventing MI5's chance to learn what Russia intends to do against an American defence base in Poland. Two assets are already dead, and Malcolm believes the
Section D learn that Tiresias is Russia's own version of Sugarhorse, but "bigger and better". Tiresias activates sleeper agent Walter Crane to detonate a nuclear suitcase bomb in Grosvenor Square at 3 pm. The team find themselves forced to turn to Connie for assistance, as she helped set up Tiresias. After Lucas, Ros and Harry break her out, they journey to a locker Connie owns containing everything on Tiresias. However, they find themselves hunted by an FSB kill squad assigned to assassina