After another long night of partying, Shaggy wakes to find that he is all alone? Where's Scooby? The gang gets all riled up when they discover that their favorite canine detective has gone missing. Well, there is no mystery that this group can't solve, but can they do it without their lovable cohort? One mystery uncovers another as they find themselves locked in a game of cat and mouse with a fiendish ghoul. Things get even more complicated now that Daphne and Fred are a couple, and Velma suddenly decides to release her inhibitions.

In another time and another galaxy, an evil Overlord and his lover, the Dark Witch, have been taking over and destroying planet after planet until in one star system, they discover that whoever will marry the virginal Princess Hubba Hubba will become de facto heir to the Clitorian solar system. But the princess as fled from her planet with a rag-tag bunch of rebels and the final battle rests with the few for the solar system and the galaxy.