With its narrative of emotionless alien duplicates replacing average folk, Don Siegel's 1956 Invasion of the Body Snatchers was the first post-war horror film to locate the monstrous in the everyday, thus marking it as a pivotal moment in American horror film history four years before Alfred Hitchcock's Psycho . Barry Keith Grant's compelling study traces Invasion's journey from 'B' movie thriller to an acknowledged classic of American cinema. Grant unpacks the film's engagement with numerous issues brewing in post-war US society, including the Cold War, McCarthyism and the changing dynamics of gender relations. Grant provides an account of Invasion's fraught production history, the distinctive contributions of key crew members, and discusses the three remakes it has inspired. He illustrates how Invasion of the Body Snatchers ' enduring popularity derives from its central metaphor for the monstrous, which has proven as flexible as that of the vampire and the zombie. In his afterword to this new edition, Grant addresses contemporary anxieties around AI and human 'replacement', bringing in such recent films as Companion (2025), The Creator (2023) and Ex Machina (2014).