Ash gets a special peek into the secret home of Latias and her brother, Latios, but this peaceful place is soon threatened by the thieves from before—Annie and Oakley—who are after both Legendary Pokémon and a mysterious jewel called the Soul Dew. These elements combined will let them control a powerful machine that normally protects against danger. When the machine malfunctions, though, it not only puts Latias and Latios at serious risk, but the entire city of Alto Mare, as well!