After traveling through mysterious gates, Ash, Goh, Chloe, and Dawn are in a parallel world where the backward flow of time has caused Pokémon to eventually revert to Eggs! Along with their parallel-world counterparts, Ash and friends investigate the... (more) gates’ origin and find the Legendary Pokémon Dialga and Palkia locked in battle. After defeating the parallel world’s Team Rocket, our heroes themselves are affected by the reversal of time, becoming younger! Desperate to stop the Legendary Pokémon’s fighting and restore space-time, they share their feelings with Dialga, Palkia, and the Mythical Pokémon Arceus, who momentarily appears to quell the conflict. With everything returned to normal, our heroes head home!