After a day of hard work on an aquaduct, the ThunderCats celebrate by some having some friendly competition. Unfortunately, the twins' victory quickly turns into a rivalry with the adult ThunderCats taking sides. While all this in-fighting is going on, the Mutants decide to attack the Lair and end up destroying the aquaduct and taking over the Lair. The ThunderKittens are also taken prisoner. Eventually, things are set right, but the end finds Lion-O musing aloud to Jaga if perhaps he's not a fit Lord because of the falling out. And apparently, Cheetara and Lion-O must have been among those who earlier disagreed because they apologize to each other.