Vlassov is a Soviet spy who defects in France. He is whisked to the U.S, where Allan Davies takes over the case. After polygraph tests and cross-examinations, Vlassov names several Western European agents who are also spying for the Soviets. Davies wants to take the listed agents into custody; meanwhile, those on the list start dying under mysterious circumstances.

When a small British owned island in the Caribbean is invaded and the world's most dangerous terrorist kidnaps a member of the Royal family, the countdown to World War 3 begins. If anyone can prevent the oncoming apocalypse it's the American President, but her closest ally the British Prime Minister appears to have gone stark raving mad.

Physicist Ted Hall is recruited to join the Manhattan Project as a teenager and goes to Los Alamos with no idea what he'll be working on. When he learns the true nature of the weapon being designed, he fears the post-war risk of a nuclear holocaust and begins to pass significant information to the Soviet Union.

The film is based on the actual events of the Portland Spy Ring trial in the U.K. A disgruntled Navy Clerk is transferred to a secret research establishment and is subsequently black-mailed/paid by Czech intelligence to procure secrets for them. He seduces the secretary who controls the most secret documents, and they enjoy the fruits of their treachery until the British authorities begin to close in on them.