In the legendary past, before Poké Balls were invented, an aura-guiding hero Pokémon named Lucario sensed two groups of armies about to clash, and a threat of a massive war…

When Giratina is discovered to be able to create parallel dimensions, it’s up to Ash and his friends to stop a mysterious stranger from using its powers for evil.

After accepting an invitation from a mysterious trainer, Ash, Misty and Brock meet Mewtwo, an artificially created Pokémon who wants to do battle.