Ravage Island is an island on Third-Earth with a powerful beacon on it that can control minds. Mumm-Ra seeks to use the beacon to make the Thundercats his slaves.
Mumm-Ra retrieves the Sword of Plundarr as the Thundercats arrive on New Thundera. While the Thundercats try to retrieve the sword and treasure, Snarf tries to find a way to free his fellow Snarfs.
While exploring New Thundera, Wilykit and Wilykat stumble upon a mysterious orb of gold and pick it up, believing it to be one of the Treasures of Thundera. However, it soon transpires that that is not the case.
Lion-O's trial to become the Thundercat Lord continues. Now he must race against Cheetara. But now the Mutants and Mumm-ra have found out about his trials. They'll stop at nothing to keep Lion-O from succeeding.
Lion-O's final test to become the true Lord of the Thundercats. He must defeat his greatest enemy, without the Sword of Omens, and no help from the other Thundercats. He must defeat Mumm-Ra.
Lion-O accidentally activates the time capsule, which hurls him back in time to Thundera exactly one day before its destruction. Meanwhile, the Mutants assault Cat's Lair with their most powerful and deadly weapon yet.
Lion-O is the hereditary Lord of the Thundercats. Now he has reached the age where he must prove his worthiness. He must face each of Thundercats in different trials/tests, without the Sword of Omens. First up, Panthro.
Weakened by the Thunderians pits below, Lion-O hangs from the bridge at Fire Rock Mountain. Hachiman finally realizes that Mumm-Ra tricked him into believing that Lion-O had turned evil.