After overhearing Snarf telling the Thunderkittens and Pumyra a story about Mumm-Rana's magic belt and Queen Luna (Luna's grandmother), Luna and Amuk journey to the white pyramid and take Mumm-Rana's belt, destroying her pyramid in the process. Pumyra tries to stop her but she gets sealed up in the pyramid. Amuk becomes jealous when Luna no longer needs him and during his ""little temper"", he accidently frees Pumyra. Then Luna forces Slithe and Monkian to help her ambush Lion-O and Panthro. During the battle with ""Princess"" Luna, Lion-O uses the sword to restore Mumm-Rana and she retakes the belt and defeats Luna. Amuk later arrives and destroys the belt.