Telefon is a spy film, starring Charles Bronson, Donald Pleasence and Lee Remick, and was directed by noted action-film director Don Siegel. The film is based on a novel about mind control by Walter Wager.

Plot

During the Cold War of the 1950s, the Soviet Union planted a number of long-term, deep-cover sleeper agents all over the United States, spies so thoroughly brainwashed that even they didn't know they were agents; they could only be activated by a special code phrase (a line from Robert Frost's poem "Stopping by Woods on a Snowy Evening" followed by their real given names). Their mission was to sabotage crucial parts of the civil and military infrastructure in the event of nuclear war.