Michael Donovan, a former soldier of fortune, is reduced to playing nursemaid for playboy George Foster in Paris. One evening, Michael is approached by Paul Valdis and Christian Ledgard about a mission. The men explain that they support Stefan Bernaldo, the people's choice to lead their small country, and need Michael to kidnap their king Peter so that he is not harmed when they attempt a bloodless coup. After a new cabinet headed by Bernaldo is put in power, they explain, the king will be restored to the throne. With George in tow, Michael goes to the country's capital, where a costume ball is being held at the palace. While George is flirting with the Countess Sonia, Michael finds the king's chambers. He gets George and the two sneak into Peter's room, where they discover that Peter is a young boy. Peter thinks that Michael and George, who are dismayed at having to kidnap the youngster, are gangsters from Chicago, and he is thrilled at the possibility of having an adventure with them. Countess Sonia enters and sounds an alarm, but feels duty bound to accompany the young king when he shows Michael a secret passageway out of the palace. While the foursome go to the safe house arranged by Valdis, the corrupt cabinet, headed by Gino, determines to find Peter before they are overthrown. Michael and the others are greeted by Augusta and Mischa, the caretakers of the hideout, and after Peter runs off crying because of Michael's rudeness, Michael tells Valdis that he wishes to quit. Valdis warns Michael that they all will be killed if Peter is returned to the palace now, and Michael decides to stay. The next day, Peter and Michael become friends when the soldier teaches the boy king how to play football, while at the palace, Valdis' men incite the people to overthrow Gino's cabinet. Later, when Sonia and George visit a gypsy camp, Sonia slips a note with their whereabouts to the fortune-teller and asks her to give it to Gino, whom Sonia does not know is dangerous. Sonia informs Peter that the cabinet's soldiers will soon arrive, and he tells Michael. Michael is proud of the boy's determination to do as his people would wish, and the pair escape to search for Bernaldo. After a hard journey, they reach the palace, where they are captured by Gino's men. They are taken to the fortress of Prince Edric, who was once a friend of Peter's family but is now in league with Gino. Gino tells Peter that he will release Michael, but after Peter is taken away, Michael is thrown in the dungeon, where George is also being held. In order to discredit Bernaldo, who has announced to the people that their beloved king would be returned that day, Gino decides to kill Peter. While Peter is being led to the firing squad, Sonia discovers Gino's treachery and frees Michael and George. Aided by Sonia and George, Michael's ferocious fighting saves the day. Michael shoots Gino as Bernaldo's soldiers arrive, and Peter is rescued. Later, Sonia persuades George to stay and marry her, and a tearful Peter awards Michael his country's highest honor before he departs.
