The film opens in Berlin in 1914, as Germany is preparing for World War I. Liebknecht (Schulze) receives a call from a fellow lawyer and revolutionary, Mr. Rauch, that documents have been found proving the German heavy arms industry's secret involvement in the buildup to the war.
Liebknecht returns to Germany on furlough in 1916, and finds himself ejected from the Reichstag for disorderly conduct.