As Ash and friends continue their journey to the next gym, they pass two islands, home to the two Pokémon Gorebyss and Huntail.  Here, they learn that these Pokémon are both evolved forms of Clamperl, but that only Gorebyss seem to come from one island while only Huntail emerge from the other.  This subtle distinction has created a stinging rivalry between the two islands, with residents of each claiming their dominant Pokémon to be superior.  As Team Rocket descends on the islands, our heroes must both defend the Pokémon from these villains and free locals of their delusions about Pokémon evolution, which are causing so much discord.