It's October 1981, and a Soviet submarine causes geopolitical chaos when it runs aground in Sweden.
The Swedes decide whether or not to attack, while tensions between the US and Soviets escalate.
Commander-in-Chief Börje Lagercrant launches an unsanctioned operation to hunt for nuclear weapons.
In the Kremlin, a power struggle is set in motion when Yuri Andropov steps into the fray.
Prime Minister Thorbjörn visits Karlskrona, foiling Börje's secret plan to attack the submarine.
Thorbjörn confirms the submarine is equipped with nuclear warheads. The world holds its breath.
Rolf Lassgård
Thorbjörn Fälldin
Anders Mossling
Ola Ullsten
Niklas Engdahl
Börje Lagercrantz
Filip Berg
Håkan Martinsson
Per Lasson
Anders Karlsson