SpongeBob and Patrick go to the source of Wow Wow Wubbzy. SpongeBob realizes he and Wubbzy are both square. Later they discover a black hole. Patrick accidently knocks Wubbzy into the black hole. Their adventure lends to Plankton's capture of Wubbzy. SpongeBob battles Plankton and destroys the machine, saving Wubbzy (who later makes Plankton run away). The episode ends with Wubbzy, Widget, Walden, and Daizy moving to Bikini Bottom (In the "End" title card, the E all sponged-up and the d crooked like Wubbzy's trademark tail Also, SpongeBob and Wubbzy are jellyfishing during the credits).