Life on an unnamed desert planet has been slowly dying for some time. A family of aliens lives on the planet, and they are searching for subterranean water which will allow them to survive. A NASA research probe lands on the planet to collect samples, and accidentally captures the aliens. The aliens are transported to planet Earth, and use their ability to manipulate electricity to escape captivity. Three of the escaped aliens head into the local desert, but the fourth and smallest alien sneaks into a passing minivan. The driver is single mother Janet Cruise, who is moving to Los Angeles with her sons. The alien moves into the new Cruise family home, and Eric Cruise soon notices the uninvited roommate. Eric and his new friend Debbie easily capture the tiny alien, but Eric quickly realizes that the alien is a sentient being who is trying to communicate with him. While Eric tries to keep the alien's existence, a duo of FBI agents have tracked down the alien and are spying on both their target and Eric.