An exciting satirical series about when the Soviet submarine U 137 ran aground at Sweden's most secret naval base in the fall of 1981 and the whole world held its breath. A major war threatens and all responsibility now rests on one man, Sweden's Prime Minister Thorbjörn Fälldin. How will he manage to prevent a world war, with a valiant foreign minister and a belligerent commander-in-chief at his side?

Prime Minister Thorbjörn Fälldin quickly heads down to Stockholm and the Government Offices where he gathers representatives from the government and the military. Meanwhile, the situation for Captain Peskov and his crew becomes increasingly desperate. Commander-in-Chief Börje Lagercrantz believes that Sweden is under attack and that the solution is a counterattack. Captain Peskov receives orders from the Kremlin to blow up the submarine if the Swedes try to board it.

In Karlskrona, Commander-in-Chief Börje Lagercrantz and Second in Chief Håkan Martinsson plan to approach the submarine on their own to measure whether there are nuclear weapons on board. They have an expert from the Swedish Defence Research Establishment to help them. The Commander-in-Chief appoints the Coast Guard's Coast Guard, Captain Hammarberg, to lead the unsanctioned operation. Meanwhile, Captain Peskov is getting worse and worse and threatens to blow up the submarine if the Swedes approach it.

Prime Minister Thorbjörn Fälldin meets with Soviet Ambassador Aleksandr Kosygin. It turns out that their plan to install a radio mast on the submarine is being thwarted by Commander-in-Chief Lagercrantz, who has exactly the same plan, but with completely different objectives. In the Kremlin, the frail Chairman Brezhnev finds it increasingly difficult to handle the situation, but receives unexpected help from the KGB's Yuri Andropov.

Prime Minister Thorbjörn Fälldin visits the naval base in Karlskrona where he is met by an unexpected international press corps. Back home in Stockholm, Foreign Minister Ola Ullsten is confronted by both the KGB and the CIA during a state visit to the Dramaten. Everyone seems to know more than the Foreign Minister. When Prime Minister Fälldin learns that the submarine is armed with nuclear weapons, everything is put to the ultimate test.

Prime Minister Thorbjörn Fälldin holds a press conference at the Government Offices in Stockholm. When he announces that the submarine is armed with nuclear weapons, the world holds its breath. Can the Prime Minister and the Soviet ambassador together solve the Gordian knot through diplomacy? And will they have time to free the submarine before the Russian fleet under Admiral Kalinin, NATO or for that matter Commander-in-Chief Börje Lagercrantz can get there first?