Scott Carey and his wife Louise are sunning themselves on their cabin cruiser, the small craft adrift on a calm sea. While his wife is below deck, a low mist passes over him. Scott, lying in the sun, is sprinkled with glittery particles that quickly evaporate. Later he is accidentally sprayed with an insecticide while driving and, in the next few days, he finds that he has begun to shrink. First just a few inches, so that his clothes no longer fit, then a little more. Soon he is only three feet tall, and a national curiosity. At six inches tall he can only live in a doll's house and even that becomes impossible when his cat breaks in. Scott flees to the cellar, his wife thinks he has been eaten by the cat and the door to the cellar is closed, trapping him in the littered room where, menaced by a giant spider, he struggles to survive.

John Putnam is a writer and an amateur stargazer with a new home out in the beautiful Arizona desert, which he enjoys with Ellen Fields, his girlfriend and a local schoolteacher. John is not trusted by the people of the small town near where he lives, certainly not by Sheriff Matt Warren, who feels protective of Ellen, and perhaps something more. One night, John and Ellen see a meteor crash in the desert. John drags his friend, Pete, out of bed to take him over to the crash site in his helicopter. Once there, John climbs down into the crater. Unfortunately, he does so alone, as Pete and Ellen wait for him. John is the only one who sees the spaceship before a landslide covers it. And John is the only one who catches a glimpse of the hideous thing inside. At first John's story seems mad, until some of the townsfolk begin acting strange - as if they aren't really who they seem to be.