In the perfectly normal town of Santa Mira, California, residents seem to be suffering from a mass hysteria: certain people feel that their relatives are not actually their relatives, even though by all objective counts they are. Things become more suspicious when Miles’ friend Jack Belicec finds an unformed, unmoving body in his house that later disappears. Jack and his wife decide to stay at Miles’ house, along with Miles’ former girlfriend Becky who is showing a renewed interest in him. At night in Miles’ greenhouse, the four find giant pod seeds that begin to sprout duplicates of all of them. Jack and his wife leave to find help, but they return transformed into emotionless replicas of their former selves. Most of the town has already been converted, and Miles and Becky are chased by a mob of pod people. They elude them temporarily, but Miles leaves Becky for a moment and returns to find her transformed. He escapes to a highway and tries to warn passers-by who think he is crazy or drunk.