A top-secret prototype is stolen from an American base. The man who stole it, Andersen, is murdered. The investigation is led by Jeff Gordon, who discovers in Andersen's papers a photo of a woman identified as Corinne Martin. Jeff Gordon escapes an assassination attempt on his way out of Martin's house and meets Corinne again, who denies any involvement in the robbery. Her husband, in the pay of foreign spies, is in possession of the "repeller". After several scuffles, Jeff Gordon arrests Martin and his accomplices. The prototype is returned to its base.

Didier Formenter, the French scientist, has just put the final touch on an invention that will be able to destroy to destroy any sort of flying apparatus. An international crime gang is very interested in stealing this equipement to sell it to the higher bidder of lawless nations. Menaced, the scientist, who was friends with Nick Carter's father, calls Nick for help. At Nice airport, Nick Carter escapes death, but that night he is unable to stop Formenter's murder. He suspects Bruno, Formenter's adoptive son, and Tonio, the owner of a bar near Formentier's home. Bruno is actually after Formenter's heritage, and for that he tries to kill Catherine, Formentier's granddaughter. Therefore, Nick Carter finds himself against more than a gang, but he will uncover the plots, in time to break every gangster apart.

Jeff Gordon, FBI agent, infiltrates a gang and finds himself in the midst of a gang war.