An expedition in remote waters finds a missing scientist who has used serums to create giant turtles, one the size of a house, the other the size of an island.; An investigator works diligently to discover the logical explanations behind the odd occurrences at a couple's newly purchased home. He is, in fact, a poltergeist who attempts to allay suspicion of his kind's existence among humans.; A businessman bigoted against robots tries to make a deal to tap the resources of a planet rich in exploding pools of radioactive oil. The natives refuse to sell their oil, since they are robots and it is too vital to them.; Mysterious billboards appear, each bearing a picture of an alien soldier. A newspaperman realizes just in time that the billboards are an attempt by a two-dimensional alien race to hide an invasion.