A kidnapped Harry Pearce is kept prisoner in an abandoned warehouse without really knowing what his captors want. When men try to kidnap Ruth, now married and with a stepson, she goes straight to MI-5 to find out what is going on. There she reveals a secret only she and knew: the location of a stash of weapons grade uranium that was headed to Baghdad justify American claims of WMDs and the invasion of Iraq. Lucas North asks for help from newly arrived CIA agent Sarah Caulfield in finding the American links to the plot. When Ruth's stepson is threatened, Malcolm puts his life on the line to save him. Written by garykmcd

When an industrial accident put a liquid natural gas plant out of commission for six months, the UK must quickly arrange for an alternate source of supply or face an energy crisis that will cripple British industry and the economy, to say nothing of its citizens' quality of life. The government is reluctant to deal with the Russians who will inevitably attach other demands to any sale, let alone give them a good price. Their only choice is to deal with Tazbekistan, a country that has recently undergone a change of government through a coup and is known for its abuse of civil rights and the use of torture on its dissidents. MI-5 is tasked to gather whatever intelligence it can about their negotiators and to also ensure that they and the Russians not seek revenge on each other in something that is akin to a blood feud. In the midst of all this the CIA, in the form Lucas North's lover Sarah Caulfield, tell MI-5 the US doesn't want the UK to make a deal with the Tazbeks and seem to be ... Written by garykmcd

MI-5 is called into action when a terrorist group takes control of a group of very rich entrepreneurs who are meeting secretly in London. The Security Service hadn't anticipated any difficulty as they had no intelligence indicating the meeting was at risk. As luck would have it, Ros Myers is on site planting a bug and so MI-5 already has an agent on the inside. The terrorists put the capitalists on trial, streaming the proceedings over the Internet and asking viewers to vote on whether they should be executed or not. The CIA want the UK government to launch an attack and even threaten to do so themselves, but Harry sees it as a sure way to get everyone killed. The Home Secretary decides it's the only way out and orders the attack. Lucas North meanwhile is trying to get information on the terrorists' leader in the hope of proving he is a phony. Separately, Jo Portman approaches Ruth Evershed suggesting she speak to Harry Pearce and rejoin the team. Written by garykmcd

The MI-5 team is still recovering from the loss of one of their own. In reviewing CCTV coverage of a riot at an immigration detention facility, Lucas North recognizes the one man who managed to escape: Oleg Darshavin, his Russian interrogator and torturer during his eight years of imprisonment. When they meet again, Darshavin offers to tell Lucas of an impending terrorist attack on the UK in return for a UK passport and money. Darshavin isn't being entirely truthful, however. Harry tells his CIA counterpart about the rumored secret Swiss meetings on a new world order and they agree to cooperate. The American, agent Sarah Caulfield's superior, learns of her affair with Lucas North and he encourages her to continue the relationship as he suspects Lucas is a double agent. He learns that Sarah has her own agenda. Written by garykmcd

Everyone is shocked to learn of CIA agent Samuel Walker's death. It's been labeled a suicide but he had made appointment less than an hour before to see Harry Pearce as he had information on the secret meeting of rogue Western agents and Chinese spies in Bern. Soon after Walker's death, another American is killed and then a British agent. As they try to sort out the connection between the murders, Ros Myers is contacted by her one-time mentor, Jack Coleville, the man who recruited her. He's now retired and asks her to read his memoirs but she soon realizes that that she is being duped. As they desperately try to find Coleville and stop him from continuing his revenge driven campaign, Sarah Caulfield sees the perfect opportunity to cover up her own activities. Written by garykmcd

MI-5 is desperate to find Ryan Baisley, a banker with Dewitts Bank who had agreed to provide MI-5 and CIA with a list of names and accounts from what the security services describe as the dirtiest bank in the world. They have Baisley in a safe house but a hit squad descends on the place killing everyone except Baisley who managed to escaped. Baisley may have also been trying to squeeze money out of the bank, leading to the hit. The Home Secretary advises Harry that it's absolutely necessary to get the information Baisley had promised within 24 hours - if the government isn't able to seize Dewitt's estimated £1.5 billion in assets, the UK will be unable to meet a major debt payment that comes due the next day. Soon however, it becomes apparent that the Home Secretary has been set up to be discredited. As MI-5 gets more information about the bank, they find a connection to the mysterious meeting in Basel, code named Nightingale, and Sarah Caulfield's connection to the group. Written by garykmcd

When a Pakistani intelligence officer is stabbed in London, Harry Pierce and Ros Meyers are told by the senior intelligence officer at the Pakistani High Commission that at virtual war is brewing between the Indian and Pakistani communities in London. They believe the leader of the planned attacks is Harish Dhillon, an Indian whose younger sister was severely beaten and is still in hospital on life support. With Sarah Caulfield having vanished, Lucas North finds a USB stick hidden in her flat. When they manage to hack into it, they find a connection between Sarah and Dhillon's controller, Victor Chatterjee and all seems to be part of the clandestine Operation Nightingale run by rogue intelligence officers. Written by garykmcd

When Pakistan seizes an Indian submarine that has strayed into its territorial waters, the world is on the brink of a war between two nuclear powers. The Prime Minister invites both parties to London for talks to calm everyone and avert a crisis but there are those who would seek to ensure the talks fail. Sarah Caulfield is a member of the conspiracy, known as Nightingale, and they are bent on starting a nuclear war. When a friendly Chinese diplomat tries to give them information about a possible attack on the peace talks, he is assassinated. MI-5 is convinced that they will cause an incident at the peace conference to push India or Pakistan over the edge. Written by garykmcd