1936. Having returned from Abyssinia, soldier of fortune Cal Jardine is convinced by his abhorrence of fascism to travel to Barcelona and help facilitate rival athletic games to the Berlin Olympics. But now he finds himself in Spain as the first shots of civil war ring out; and friendship, love, and political conviction converge to persuade Jardine to stay and once again embroil himself in foreign war. Discovering that the British athletes attending the games are keen to enlist for the fight, Jardine agrees to train them into a professional force. With old army comrade Vince Castellano and his beautiful interpreter Florencia Gardiola by his side, Jardine leads the athletes through the street battles of Barcelona and onto the fighting in the Catalan countryside, acquiring famous friends and effective allies along the way - as well as dangerous enemies. Manfred Drecker is a German communist diehard, who brooks no moral qualms in his deadly determination to see Spain transformed into a socialist state under the rule of the Soviet Union.
Having witnessed his trickery and torture, Jardine is already on his guard against Drecker; but when murderous betrayal blights his previous fortune, Jardine will go to any lengths to seek suitable revenge -