Retired agent Matt Helm is re-activated in order to stop an evil organization from exploding an atom bomb over the USA and starting WWIII.
The film begins with a shot of the United States Capitol being destroyed. It is actually a scale model being used in the demonstration of a heliobeam weapon in the headquarters of the Bureau of International Government and Order ("BIG O"). BIG O is a secret organization with the goal of world domination that previously appeared in ''The Silencers (film)''.
Helm is sent to the ICE (Intelligence and Counter Espionage) Training Headquarters to uncover a traitor in the organisation. While there he meets ICE agent Sheila Sommers, a test pilot who has been recovered from a Central American jungle with no memory of what happened to the experimental flying saucer she flew. Due to the electo-magnetic power of the saucer, only a woman is able to fly it, males of the species are killed by the energy.
Matt Helm is assigned by his secret agency, ICE, to bring down an evil count named Contini, who is trying to collapse the world economy by stealing a billion dollars in gold.
The series was loosely based upon the literary character Matt Helm, who had been created and introduced by Donald Hamilton in his 1960 novel, Death of a Citizen. The concept of the series sees Matt Helm, a retired spy, opening a private detective business.