Dr. Millie Beenhell discovers an outbreak of "mass hysteria" in her small town of Santa Maria. Her patients are claiming that their relatives and loved ones have changed overnight as if their bodies have been abducted by some foreign alien. The transformed creatures become unscrupulous salespeople obsessively hawking their counterfeit wares at all costs. The plot reveals a pod like plant being distributed by the alien hucksters that absorbs the appearance of its victim while asleep leaving the true person dead. We soon realize the earth is under a worldwide invasion leaving no human immune to the hell of the eternal pitch.