Beastly looking mice (that look more like rats) are in the Castle of Lions wreaking havoc - things are exploding, catching on fire...you name it. After some investigating with the Castle scanners, it's determined that the pests are holed up in the room where most if not all of the Castle's circuitry to its computer controls are located. The men of the Voltron Force head that way to investigate only to end up getting in an exchange of laser fire with the beasts (the alien mice can shoot red beams out of their eyes - scary!).