In this animated adventure, our heroes head to Sinnoh to learn about the region's past. After receiving a mysterious message from the Mythical Pokémon Arceus, they meet up with Brock, and the group heads to Mount Coronet to investigate. There, they find a rampaging Heatran and the commanders of Team Galactic, who are determined to find their missing leader by opening a gate between dimensions. Joined by a trio of Legendary Pokémon and Sinnoh Champion Cynthia, our heroes must give it their all to stop Sinnoh from being destroyed!