Michael Donovan (McLaglen), a soldier of fortune and former United States Marine Corps colonel, is fed up with his latest job: keeping spoiled playboy George Foster (Michael Whalen) out of trouble from women and liquor. Thus, he is eager to accept when revolutionaries Valdis (Lumsden Hare) and Ledgard (Walter Kingsford) want to hire him to kidnap King Peter II, ruler of a country somewhere in the Balkans. When a drunken Foster wakes up and interrupts their meeting, Donovan calls him his aide.