A small-town doctor learns that the population of his community is being replaced by emotionless alien duplicates.
Near the end of the Korean War, a platoon of U.S. soldiers is captured by communists and brainwashed. Following the war, the platoon is returned home, and Sergeant Raymond Shaw is lauded as a hero by the rest of his platoon. However, the platoon commander, Captain Bennett Marco, finds himself plagued by strange nightmares and soon races to uncover a terrible plot.
After an asteroid draws an astronaut and his ship to its surface, he is miniaturized by the phantom planet's exotic atmosphere.
