Our heroes find an Eevee tied to a tree, and seeing the collar around its neck, return it to its owner. At the house of the owner is an 'evolution party' being held, where lots of Pokémon have been evolved with stones. The Eevee of Mikey - the trainer of the Pokémon they found - was to be the star of the party. Now, Mikey's three older brothers, who have a Jolteon, Vaporeon and Flareon, are glad to see Eevee back so it can evolve. They say it has to so it can be useful for when Mikey is old enough to be a trainer. But Mikey isn't sure he WANTS it to evolve. Misty encourages him to tell his brothers that, as a responsible trainer.
But Team Rocket crashes the party - stealing, in the span of about ten seconds - ALL the food, ALL the evolution stones and ALL the Pokémon! Pidgeotto follows an ink trail left by Misty's stolen Horsea, and leads everyone to Team Rocket, who fight them with Arbok and Weezing. Everyone manages to take back their Pokémon, evolution stones, etc, but the Rockets keep a hold of Eevee. Mikey's brothers fight with their evolution Pokémon, but Arbok and Weezing defeat them. So, Mikey and Eevee fight, winning their first battle. Mikey's brothers realise that Eevee can be strong without evolving, and agree not to force him.