The heroes encounter a man named Adam who's searching for treasure. They decide to accompany him to find an old ship, which is told to have lots of treasure on it. Just as they take the submarine down, they also encounter Team Rocket, who is also determined to take the treasure, which is connected to the Relicanth Adam saw earlier.

Since they have to wait for the boat to Mossdeep City, the heroes spend some time with other trainers, who want to get physically fit for the battles. While Brock, May, Max, even Team Rocket exercise, Ash has a Double Battle with the coach, Rocky, who shows how much his Pokémon can be in sync.