Oshawott breaks up a fight between Ash and Iris on their way to Striaton City. Ash learns, with Pikachu's help, that Oshawott's been following Ash since he left Nuvema Town and wants to join Ash's team. Pikachu is less than thrilled as Oshawott is extremely jealous of him always being with Ash. Professor Juniper sends Ash Oshawott's Pokéball.
While looking for Oshawott, Ash, Iris and Pikachu fall into a sand trap they learn has been built by Sandile. They're helped by a boy named Dan who's family operate a Resort Spa and Hotel. The resort's hot sand baths have been ruined by Sandile's digging of sand traps everywhere, bringing down trees and creating a huge mess. The gang find Oshawott enjoying the warm sand when they're creeped up on by the Sunglass-wearing leader of the Sandile.
The Sandile leader attempts to carry away first Axew and then Pikachu and Oshawott. Team Rocket complicates matters when they attempt to steal Pikachu, Oshawott and Sandile. A group of wild Sandile come to their rescue. After Team Rocket dissapears, the group find that the Sandile are just trying to protect and save all Pokémon (including a group of wild Patrat, Deerling and Pidove) from incoming hot geysers. When the wild Pokémon get trapped between boiling hot water, the Sandile make a bridge which Ash uses to encourage the scared Pokémon.
Once the Pokémon are saved, the Resort returns to normal - with the Sand spas being replaced by Hot Springs.