After crashing their spaceship in the Nevada desert, Klatu, Lek, and their sister Ploo go to Las Vegas in search of the one mechanic who can fix it.

Siblings Klatu, Lek, and Ploo from the planet Loogl return to Las Vegas where they discover an impending invasion of earth by evil aliens disguised as Elvis impersonators. After thier spaceship is taken by the Great Ones, Ploo, Klatu, and Lek return to Las Vegas. There they discover an infestation of Elvis impersonators, in town for a convention. Klatu, Lek, and Ploo are sure the odd-looking humans are up to no good, and it turns out that they're...