Giovanni, the leader of Team Rocket, had ambitious plans to take over the world, involving his latest experiment, a powerful clone of Mew—Mewtwo. Mewtwo is very powerful, and also very smart—smart enough to not want to be controlled by Giovanni. It escaped from the lab, and now Mewtwo begins to concoct its own scheme, clandestinely inviting a number of Pokémon Trainers to the ultimate test. Of course, if it's an event for talented Trainers, Ash Ketchum will be right in the front row!
Ash's excitement turns to fear and anger when Mewtwo reveals its plan for domination, creating powerful clones of all of the kids' Pokémon so it can even the "imbalance" between Pokémon and their Trainers. Despite Ash's protests, Mewtwo refuses to believe that Pokémon and people can be friends. But faced with the determination of a young Trainer and the love of his Pokémon, Mewtwo just might have to reconsider, especially when pitted against the power of the mysterious Mew!