The perennially-popular canine sleuth (with a weakness for snack treats) has an out-of-this world adventure in this direct-to-video animated feature. Scooby, Shaggy, and their friends are traveling through the desert when their van breaks down. Stuck with nowhere to go, they head for the nearest town, which they discover is crawling with UFO enthusiasts. The gang quickly learns that the UFO buffs have picked this meeting place for a very good reason -- some actual extraterrestrials have landed in a flying saucer, and it doesn't take long for Scooby to notice that they aren't very friendly. Scooby-Doo and the Alien Invaders features the voice talents of Mark Hamill, Jennifer Hale, Scott Innes, Kevin Michael Richardson, B.J. Ward, and Frank Welker; actress and musician Jennifer Love Hewitt performs the theme song.
by Mark Deming synopsis