The inhabitants of the planet Thundera evacuate before it is destroyed. These were chased by a group of mutants. All but among their escape ships was destroyed. Only a small band of Thunderans (Thundercats) remained. With just half engine power had to decide on a path for the planet. Their ship was commanded by jaga whilst the other seven were in their tubes. Jaga died on their journey and their ship crashed there. So on they left friends with several groups within the area and so they designed a fortress. Mumm-Ra the embodiment of evil, in addition to the mutants that destroyed the remainder of the Thunderans certainly really are a threat. But Lion-O, the newest leader of the Thundercatsalong together with his weapon that the"Sword of Omens" may allow the Thundercats to have a standing chance.