When a tangle with Team Rocket leaves Pikachu desperately exhausted, a young passerby offers to restore Pikachu’s energy, but only if the humans present promise never to reveal to another soul what they are about to see. This trainer then proceeds to guide Ash and friends to a legendary lake that somehow seems to restore energy to the Electric Pokémon that live along its banks. Unfortunately, however, Team Rocket manages to tail the young trainers as they enter. Jessie and James are quick to make plans to lay waste to the serene lake, trading its pristine essence for personal gain.