The Fourth Protocol (film) - Plot

Plot

The plot centres on a secret 1968 East-West agreement to halt nuclear proliferation. One of the clauses, the Fourth Protocol, forbids the non-conventional delivery of a nuclear weapon to a target.

MI5 agent John Preston (Michael Caine) breaks into the residence of British government official George Berenson (Anton Rodgers) on New Year's Eve and finds a number of top secret NATO files that should not have been there. He reports his findings to high-ranking British Secret Service official Sir Nigel Irvine (Ian Richardson), who deals with the leak. However, Preston's unauthorized action has embarrassed the acting-Director of MI5, Brian Harcourt-Smith (Julian Glover), so as punishment for his insubordination, Preston is relegated to lowly "Airports and Ports".

Meanwhile, KGB agent Major Valeri Petrofsky (Pierce Brosnan) is sent on a mission to Great Britain by General Govershin (Alan North), the head of the KGB. One of Govershin's subordinates, Borisov (Ned Beatty), complains to his old friend General Karpov (Ray McAnally), about his espionage department being stripped of resources and personnel, particularly his star agent Petrofsky. A surprised Karpov quietly investigates and learns about Petrofsky's unsanctioned mission – to violate the Fourth Protocol by assembling and detonating an atomic device so that it will appear to be a nuclear accident at a nearby military base. It is intended to strain British-US relations and strengthen the anti-nuclear movement in advance of an election in favour of the Soviet Union.

In Glasgow, a Russian sailor is struck by a truck while fleeing from a port guard. Among the dead man's possessions, Preston finds a disk of polonium, which could only be useful as a component of a detonator for an atomic bomb. He informs Harcourt-Smith, but is promptly suspended, as Harcourt-Smith believes that Preston is manufacturing a fake incident to work his way back into MI5. Luckily however, Preston has the confidence of Sir Bernard Hemmings (Michael Gough), the gravely-ill Director of MI5, as well as Irvine, who is happy to sidestep Harcourt-Smith's directives. Preston sets to work and eventually comes across Winkler (Jiri Stanislav), a known Czech KGB agent, and tails him from the airport.

Meanwhile, Petrofsky meets another KGB agent, Irina Vassilievna (Joanna Cassidy), a bomb expert who is pretending to be his wife. Under her guidance, they assemble the device from seemingly-harmless items and she sets it on a two-hour delay per their instructions. Later, unbeknownst to Petrofsky, Vassilievna follows her own orders, resetting the delay to zero. After sleeping with Petrofsky, she finds his own secret order to eliminate her and tries to warn him about the double-cross, but he kills her before she can.

Afterwards, Petrofsky is observed contacting Winkler. Preston tracks him to Ipswich, loses him, then finds him again. Preston eventually realises that Petrofsky's target is RAF Baywaters, and locates Petrofsky's house, which lies right next to the base.

When Petrofsky starts to activate the bomb, on an impulse, he checks the timer first and realises he has been betrayed. At that moment, an SAS team storms the house. After a struggle, Preston subdues and disables Petrofsky. However, to Preston's outrage, one of the SAS team cold-bloodedly executes Petrofsky, explaining afterwards that he had orders to do so.

At Hemming's funeral, Preston is unsurprised to find Irvine secretly meeting with General Karpov. Preston had become suspicious when known KGB agent Winkler was used as a courier, making it easy to follow him, and also when Petrofsky was killed instead of being captured for questioning. He surmised that discrediting Govershin would benefit both Irvine and Karpov. However, Preston does not see any point in exposing them and leaves after expressing his contempt for their cynical power play.