Kent Fowler manages a program that sends men to Jupiter. The men are converted to Lopers, a type of lifeform that can withstand the pressure of Jupiter’s atmosphere. They are being sent there to investigate how to prevent Jupiter’s pressure from drawing in the Earth and destroying mankind. The problem is, Fowler has sent five men over there, and none of them have come back. Feeling pressure from his colleagues, Fowler decides to send himself and his dog, Towser, to Jupiter. They are both converted into Lopers, and now Towser can speak. He quickly tells Fowler the formula needed to prevent the encroaching apocalypse. They wander Jupiter, discussing their time together, and they realize that, despite having solved the mystery, they don’t want to go back to Earth. Instead, they decide to remain Lopers on Jupiter.