In the 1940s, a small band of underground paramilitaries attempt to fight back against the Soviet-backed security ministry in post-war Poland. Determined to fight for their country's future, the group goes to extreme lengths to make their voice heard.

Operation Danube was the cover name for the invasion of Czechoslovakia by Warsaw Pact armies in August 1968. The fleet of Polish tanks which arrive to liberate their neighbor, ostensibly threatened by a counter-revolution, includes the old tank nicknamed Ladybird, which is the last to leave the barracks.