In 1937, the civil war is raging in Spain. The National Socialists support Franco's regime in the fight against the partisans. In return, the Spaniards are to test the newly developed nerve agent Tabun from IG Farben. The German scout Fred Laurenz is infiltrated into the notorious fascist legion "Condor" and comes into possession of the top-secret formula. When he wants to smuggle them into the Soviet Union to prevent their use, he is taken prisoner and deported to the Spanish colony of Rio de Oro in West Africa. Isolated from his comrades-in-arms, but with a firm belief in his mission, Laurenz surpasses himself and escapes from the notorious prison. A deadly chase through the desert begins...