Employed by a Pittsburgh steel plant Matt Cvetic (portrayed by Frank Lovejoy) poses as a Communist to secure information for the FBI. Even his own family believes he is a Red and is hostile toward him. The Communists, with Cvetic in on the discussion, plot a strike at North American. Meantime Cvetic discovers his son's teacher, Dorothy Hart, also is a Communist, but she repudiates the party. She learns Cvetic is not really a Communist and he helps her escape after the Communists kill an FBI man assigned to guard her. Cvetic's activities are instrumental in rounding up 11 Red leaders. He testifies against them before the congressional un-American activities committee, at the same time clearing his own name.
The Smashing, Socking, Sizzling Motion Picture... That Performs an Invaluable Public Service... Ripping the Veil From the Communist Underground Menace... To Our Country's Freedom. Warner Bros. 84 mins.