Murderers' Row
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.
With the aid of a mole, BIG O conducts a worldwide assassination campaign against various secret agents working for ICE (Intelligence Counter Espionage). Matt Helm (Dean Martin) fakes his own death in preparation for investigating the scheme undetected.
Helm meets his boss, Mac (James Gregory), for a mission briefing. Helm is to track down the missing Dr. Solaris (Richard Eastham), who has developed the powerful heliobeam weapon, a device that uses the concentrated power of sunlight for mass destruction. Helm is told if he can not rescue Solaris he is to kill him, and if captured to kill himself, lest BIG O brainwash him.
Posing as a Chicago gangster named Jim Peters, an alias of "Lash" Petroni, Helm travels to the French Riviera to follow his only lead, Solaris's daughter, Suzie (Ann-Margret). Concerned about her father's disappearance, Suzie helps Matt infiltrate the island lair of the diabolical Julian Wall (Karl Malden), blow it up, and thereby save Washington, D.C. from being destroyed.
good versus evil, cult, violence