#66 "The Evolution Solution"

    Ash is to start his training for Pokémon League, which will start in about 2 months. He ends up at Sea Foam Island to talk to Professor Westwood, an expert who helped write the Pokedex. Right now, both Professors (Oak and Westwood) are working on solving the mystery of Slowpoke evolving into Slowbro with a Shellder. Westwood has a Slowpoke, which Psyduck befriends, because they are both dopey and understand each other. Meanwhile, Jessie and James have orders to steal Pokémon from Westwood, and catch a Shellder so that they can evolve Slowpoke.

    Slowpoke is reluctant to evolve, but Team Rocket eventually manage to get Shellder to bite its tail, and it does evolve. Then, predictably, Psyduck with Slowbro fight back, and sends the villains flying. Westwood, seeing Slowpoke actually evolve before his eyes, considers the mystery solved. I think I missed something. Psyduck and Slowbro say goodbye.