On July 1, 1968, America, Britain and Russia signed a treaty to halt the spread of nuclear weapons.The powers then added four extra clauses. The most secret of them was, and remains, the final. On winter, the Chairman of the KGB hatches a plan to breach this Fourth Protocol and destroy NATO. He sends an agent, Major Petrofsky (Pierece Brosnan), to assemble the operation. It is now up to MI6 agent John Preston (Michael Caine), who now must race against an unknown deadline to stop him and his devasting mission.