On their way to May's first contest in Slateport City, Ash and gang travel across the sea on a motorboat. After Team Rocket fails in their latest attempt to steal Ash's Pikachu, the boat stops working. Drifting along, they spot a large, abandoned ship and decide to go inside upon seeing a smaller boat off to the side.
Inside, they meet up with Tommy, a trainer who lost his Marshtomp on the ship long ago. He promises to give Ash and company a lift after he is done searching. Several Pokémon start to go missing and soon May, Max and Team Rocket are captured too. A Swampert and a Spinarak reveal themselves as the culprits.
Ash, Brock, Pikachu and Tommy soon come across the Swampert and Tommy recognizes the Swampert as his Marshtomp, but it retreats further into the ship. After saving the others, Tommy reunites with his lost friend and apologizes for leaving it behind. After thwarting another of Team Rocket's schemes, Ash and company leave on Tommy's boat for Slateport.
When it showed Max waking up, finding himself captured in Spinarak's String Shot, along with May's Torchic and Meowth, it showed they looked to be at least ten feet in the air. However, when Meowth cut Max loose, it showed Meowth and Torchic to be low enough for Max to reach up and attempt to help May's Torchic down. This was repeatedly shown through the episode as the captured were shown again and again to be at least ten feet in the air.
Near the end of the episode when Tommy was taking everyone to Slateport, May says she's excited for her Contest, and Ash says he's excited for his Slateport City Gym battle, though there is no Gym in Slateport. He may have been referring to his battle with Wattson in Mauville City.
Ash's Badge case, consisting of a red Poké Ball silhouette, does not get changed into a red rectangle.