Germany, 1923. Economic ruin, hunger and strikes. Workers called to fight by the communist Nils Unger seize an arsenal of weapons and turn each building into a fortress. The Social Democrat Busch does not fulfill Unger's order to blow up the bridge across the Elbe, and the Reichswehr troops enter the city. The massacre begins. Nils Unger is arrested. Busch, tied to the enemy's helper Dr. Mays, betrays the rebels under interrogation. The rebels face the trial. To avoid political publicity during the trial, Nils Unger is declared insane, but he manages to escape. And again one can hear his call "Keep the rifles!" on the streets of Hamburg.