The Iron Curtain (1948)

Set against the backdrop of World War II, the story revolves around Igor Gouzenko, a Soviet cipher clerk portrayed by Dana Andrews, who is stationed at the U.S.S.R. Embassy in Ottawa. After receiving extensive training, Gouzenko defects, bringing with him 109 pages of explosive information that expose high-ranking Canadian officials and reveal a network of sleeper cells aimed at acquiring nuclear secrets in North America. The fallout from his revelations, publicized by American journalist Drew Pearson in 1946, ignited a scandal that rocked Canada, Britain, and the United States, altering the course of international relations.