The Spanish Civil War in the year 1936. Five brigadiers are singled out to stay behind in the Spanish Sierras and fend off the fascist enemy while the rest of the troops recede. They are supposed to rendezvous with a radio operator, but when they get to the meeting point there is nobody there. In search for the missing man, Kommissar Wittig is shot. Before his death he hands over a piece of paper with an important message which the remaining men have to transport across enemy lines. The paper is torn into five pieces and each piece is hidden in a cartridge. An odyssey across the mountain desert begins - with constant fear of enemy fire and dehydration.