In space, Betty must stop the evil Nuclea from stealing the galaxy's power resources. On Earth, Betty's parents are away for the weekend and Betty and Purssy are forced to attend a sleepover with Penelope, Megan, Sarah, and Penelope's pet cat "Poopsie". / On Earth, Betty's favorite musical artist, "Missy Miss" is coming to town, and everyone in school wants to go. In space, Betty, Sparky, and X-5 fall under the spell of Maximus' Dream-Invader, his latest invention, with which he can enter peoples dreams and even manipulate them. With this device, he hopes to uncover the secret location of Betty's home planet.