The screenplay was inspired by a May 1951 Reader's Digest article by J. Edgar Hoover entitled "The Crime of the Century: The Case of the A-Bomb Spies."

The article covers the meeting of German physicist and atomic spy Klaus Fuchs and American chemist Harry Gold as well as details of the Soviet espionage network in the United States.

The film substitutes real atomic spying with vague top secret scientific programs.

Professor Albert Kafer is the space-weapons scientist who is being forced by the Soviets into cooperating with them, as his son is under threat, while Alexi Laschenkov is the top Eastern-Bloc spy.

[2] Using state of the art technology, such as an early miniature video camera, and ingenious methods like a roomful of foreign language lip readers, the G-men crack the case and with the help of the US Coast Guard rescue the professor before he can be spirited away by submarine.