The Fourth Protocol
Frederick Forsyth
 On New Year's Eve 1986, professional thief Jim Rawlings breaks into the apartment of a senior civil servant, and unintentionally discovers stolen top secret documents. Although one of the most notorious crooks in London, he is enough of a patriot to send the documents, anonymously, to MI5 so that they might find the traitor. In Moscow, the British traitor Kim Philby drafts a memorandum for the General Secretary (Soviet president) stating that, if the Labour Party wins the next general election in the UK (scheduled for sometime in the subsequent eighteen months), the "hard left" of the party will oust the moderate, populist Neil Kinnock in favour of a radical new leader who will adopt a true Marxist-Leninist manifesto, including the expulsion of all American forces from England and the country's withdrawal from and repudiation of the North Atlantic Treaty Organization (NATO). In conjunction with a GRU general, an academic named Krilov and a master strategist, Philby devises "Plan Aurora" to ensure a Labour victory by exploiting the party's support for unilateral disarmament—although it is noted that Krilov has come up with most of the plan's strategy. MI5 officer John Preston, who was exploring hard left infiltration of the Labour party, investigates the stolen documents and finds that they were leaked by George Berenson, a passionate anti-communist and supporter of South Africa. Berenson passed on the documents to Jan Marais, a man he believes is a South African diplomat, but is in fact a Russian false flag agent. SIS chief Sir Nigel Irvine confronts Berenson with the truth and "turns him", using him to pass disinformation to the KGB. Preston is being pushed towards retirement by a his MI5 superior, but is worried about his retirement finances, wanting custody of his son. As part of Plan Aurora, Russian agent Valeri Petrofsky arrives under deep cover in England and sets up home in Ipswich. From there, he travels around the country collecting packages from various couriers who have smuggled them into the country as harmless-looking artefacts. One of the couriers, disguised as a sailor, is attacked by neds in Glasgow and taken to hospital, where he commits suicide rather than submit to questioning. Preston investigates and finds three out-of-place looking metal discs in a tobacco tin in his gunny sack. He shows the discs to a metallurgist who identifies the outer two as aluminum but the other as polonium, a key element in the initiator of an atomic bomb. Preston reports his findings to his MI5 superior, who ignores them and has Preston taken off the politically embarrassing case. Sir Nigel Irvine, however, suspects that a major intelligence operation is under way, and has Preston work unofficially for him to search for other Russian couriers. At the same time, he uses Berenson to pass a deliberate piece of disinformation to the KGB. In Moscow, the director of operations for the KGB, General Karpov, discovers Aurora's existence. He identifies that the General Secretary is responsible, and blackmails Krilov into revealing the plan; in contravention of the Fourth Protocol to the 1968 Nuclear Non-Proliferation Treaty a small atomic device is to be smuggled (via its component parts) into England, and be exploded near Bentwaters Air Force Base a week before the general election. Evidence will be left that the explosion was an accidental detonation of an American weapon, leading to a wave of anti-Americanism, support for unilateral disarmament and for the only major party committed to disarmament, the Labour Party. The day after they win the election, the hard left will take over and begin to dismantle the Western alliance in Europe. Meanwhile, Preston tries in vain to uncover other couriers connected to the operation. A month into the investigation, a bumbling Czech agent under the name Franz Winkler arrives at Heathrow with a forged passport and is followed to a house in Chesterfield. Preston's patience is rewarded when Petrofsky shows up to use the radio transmitter that is located there. He trails Petrofsky to his rented house, where the bomb has been assembled. An SAS team is called in to storm the house, and manage to wound Petrofsky before he can detonate the bomb. Against Preston's express wishes, the leader of the SAS team shoots the Russian agent in the head afterwards. Before dying Petrofsky manages to say one last word: “Philby”. Preston confronts Sir Nigel Irvine with his theory that the operation was deliberately blown by Philby. Philby did not know Petrofksy's location but instead, sent Franz Winkler, with an obviously forged passport, to the location of the transmitter, and ultimately, to Petrofsky. Sir Nigel admits to sabotaging the KGB's British operation by leaking disinformation through Berenson to General Karpov, that they were closing in on their suspect. In turn, Karpov (and not Philby) sent Winkler, sabotaging Plan Aurora. By sending Winkler, Karpov is thwarting a British publicity victory as Sir Nigel understood the implication, that Petrofsky must not be taken alive or exposed in the media. At the novel's end, Preston's MI5 superior and adversary is denied a senior leadership role due to his misjudgment in the case and subsequently resigns from MI5 altogether. Preston also resigns, but through Sir Nigel Irvine, finds lucrative private-sector employment that enables him to obtain full custody of his son. Marais is taken into custody by South African intelligence and Berenson's work is left unusable to the KGB, as Sir Nigel, using his own spy network, intends to plant the suspicion that Berenson was in fact a double agent, and so his information will be considered suspect.