Ash now begins his new journey in Unova, accompanied by Iris and her Axew. During an argument, their old friend Oshawott appeared out of nowhere (whoa). Oshawott was happy to see Ash again since it followed them all the way out here and wanted to come along with them. Ash tried catching it but then he realized that Oshawott was the same one from Professor Juniper's lab. After retrieving it's Poké Ball from Professor Juniper, Oshawott disappears just as quickly as it appeared. Soon Ash and Iris fall into a hole which, according to a young boy named Dan, was caused by a Sandile and a whole group. What is the cause of the Sandile Uprising? And can Ash find Oshawott so he can come along with him?
As they go to Striaton City, Ash and Iris bicker, as they claim one follows the other. Iris thinks he needs help through Unova, but Ash tells he did not ask for her help. They both argue, but notice an Oshawott. The Oshawott approaches Ash, who sees it is the one that helped them defeat Team Rocket. Iris thinks Oshawott followed her and likes it being cute. However, Oshawott is not impressed and goes on Ash, knocking Pikachu down. Pikachu uses Thunderbolt, but Oshawott uses its scalchop to reflect the attack, which hits Ash. Iris laughs, but thinks Oshawott wants to come with him. Ash appreciates that Oshawott saved them, so goes to capture it. However, the Poké Ball bounces off, so Ash sees this is Prof. Juniper's Oshawott.
Ash and Iris contact Prof. Juniper and tell what happened to Oshawott. Juniper was worried where Oshawott went, but gives Ash Oshawott's Poké Ball and warns to keep an eye on him. She logs out, but Ash and Iris see Oshawott disappeared. Iris tells she could help him, since Ash is acting like a little kid. They go to search, but fall in a hole. A boy appears, telling this was done by Sandile. Team Rocket run to get to the twerps, but fall down a hole, though they land gracefully. They notice an angry Sandile with sunglasses. The boy is Dan, of the local spa center. Ash and Iris tell they like spa centers, but Dan warns them the center is closed because of Sandile. Dan remembers that when he and his father were treating guests, a bunch of Sandile appeared. Normally they are calm, but then they started to destroy the place, digging holes to vandalize the spa.
They don't understand what could make Sandile attack out of sudden. Ash tells they need to do research, so he and Pikachu burrow themselves in the sand. Iris thinks that he wants to relax in the spa, though her Axew joins them. Team Rocket observes and plan on catching the Pokémon, but a Sandile with sunglasses appears before them. They shoo it off, so Sandile digs away. Iris reminds Ash they were supposed to search for Oshawott. Ash comes out of the sand, but sees Oshawott is also relaxing in the sand. The Sandile with sunglasses emerges, so Dan recognizes it to be the leader. It takes Axew away, so Pikachu goes to electrocute it. However, Iris warns Ash this would hurt Axew, so Ash, Iris, Oshawott and Pikachu try to take it out. However, Pikachu's ear tickle Sandile, who sneezes, then takes Pikachu and Oshawott away.
Sandile walks away, but is captured by Team Rocket. They drive away, with Meowth throwing the smokebomb to distract the twerps. As they continue, Team Rocket's vehicle gets stopped. Ash, Iris and Dan go up and see a bunch of Sandile surrounding the vehicle. They dig out, causing the vehicle to fall down, so Team Rocket goes out, while the Sandile leader is freed. The leader drops Pikachu and Oshawott to a bunch of Pokémon. The Sandile escort the Pokémon, as the geysers come out. Dan thinks that the Sandile came to warn them of the danger. Ash goes to Pikachu and Oshawott, while the water boils out, causing the Pokémon to be trapped on a small island, which is falling apart. Ash goes to save them, but runs out of the boiling river.
However, the Sandile bite each other's tails, connecting each other to make a bridge. Ash tells the Pokémon to cross the Sandile bridge, but they are too afraid. Ash crosses it and ensures there is nothing to be afraid off. After the last one crossed the bridge, the island begins to shatter, so Ash grabs the Sandile. A geyser emerges and goes to hit Ash. However, Oshawott comes and uses Water Gun to stop it. Oshawott begins to fall down in the river, but Ash calls him back. Suddenly, Ash loses the Sandile, but Iris gets his hand, saving him. The Sandile make a pillar to transport Ash and Iris, then fall down. Ash and Iris are pleased, nonetheless. Later, Ash and Iris relax in the hot spring, for the geysers released the hot water, making a new attraction. Dan and his father are glad they have the hot springs. Meanwhile, the Sandile with sunglasses digs out and laughs.
- "So why are you coming along with me anyway?" - Ash
- "It's not that I'm coming along with you it's that your coming along with me. Get it?" - Iris
- "Oh please!" - Ash
- "It's true!" - Iris
- "Man!" - Ash
- "Your such a kid!" - Iris
- "Oh yeah? Your such a kid too!" - Ash
- "Pika-Pika!" - Pikachu
- "You've got some nerve saying that to me!" - Iris
(They turned to see Oshawott in surprise)
- "Osh-a-wott." - Oshawott
- "Are you the Oshawott from Professor Juniper's lab?" - Ash
- "Pik-a?" - Pikachu
- "Oshawott, Oshawott, Oshawott, Oshawott!" - Oshawott
- "Professor Oak's Live Caster": Pokédex
- "Who's That Pokémon?": Sandile
- This is the only episode where Team Rocket does not fall in a hole in a comical fashion.
- When the water rushed in and made the island it was shaped like the Team Aqua symbol.
- During the initial English dub airing, the "Who's That Pokémon?" was not present in the UK airing.
- The first time this episode aired, "Who's that Pokémon?" did not appear. That changed in future re-airings, with it being Sandile.
The Poké Ball popping sound effect is heard after the Prof. Juniper's Oshawott flashback.