An Ecology Inspector (EI) comes to Thundera to inspect the new Cats Lair. His ship uses the SWAN system (Space Way Airborn Navigations) to direct him to planets all over the universe. When he arrives on Thundera, he gets ambushed by Two-Time (see Return to Thundera, Part III). Two-Time uses a hologram to make the EI's ship crash into a mountain, and then when the Thundercats come to rescue the EI in the Feliner, Two-Time uses the hologram again. Lion-O manages to fly around the mountain and lands the Feliner. Meanwhile, Two-Time flies to new Cats Lair in his spaceship, Dome-Down. He actually picks up the whole Lair and keeps it inside Dome-Down. The Thundercats fix the Feliner, rescue the EI, and then fly to catch Dome-Down. Once they catch the spaceship, Lion-O uses the sword to defeat Two-Time and send him flying out of the ship. Then they return Cats Lair to its proper place.
