The legendary Pokémon Celebi and the boy Sam travel from the past to the present while being chased by a hunter. Sam falls behind and encounter Ash, Misty, Brock and their Pokemons, and the team help Sam to find Celebi. Meanwhile, a high-ranking member of Team Rocket, the Iron Masked Marauder tries to capture Celebi to help him create a giant monster to overthrow Giovanni and take control of Team Rocket.