Ray Milland plays Allen Fields, a scientist working for the Atomic Power Commission in Washington D.C., and stealing secret information for a foreign power. A telephone-ring code alerts Fields to his undercover cohort's requests for new information and the physical contact communicates with a dropped piece of trash on which information is written. The information Fields photographs on microfilm and hands off to his contact is passed again and again to a chain of secret agents who smuggle it out of the country. As Fields steals more information he takes more chances which begin to play on his conscience. When at one point some purloined information accidentally falls into the hands of the police, the FBI become alerted. Fields flees to New York where he waits in a run down apartment on the upper West Side of the city for a phone call to instruct him as to how to escape the authorities. When the FBI get closer a shattering confrontation results.