As our heroes set out on their journey again, they encounter a waterfall. Brock ties a rope to a rock and, with Lotad's help, wraps it on a branch above the waterfall. After Brock helps everyone up the rope, they discover a lake filled with Mudkip. Brock notices a baby being washed away in the current and sends Lotad to help. Lotad gets caught as well and a larger Mudkip jumps in and saves them both. At this point an older man comes out, afraid that Ash and company are trying to steal the Mudkip. They explained what happened and are invited in for lunch.
The man explains that he takes care of and raises the Mudkip in the lake. He even shows them a baby Mudkip hatching out of an egg. He explains that while most Mudkip leave to explore the world, the larger one stayed to protect the babies. Throughout lunch, Team Rocket is debating whether or not to enter the lake area. They of course, do so, knocking over some cans that the caretaker had set up as sort of a security system. The man hears the noise and goes to inspect what is going on. Team Rocket destroys the dam so that the Mudkip are washed away and they can catch them easier. Brock uses his Pokémon to save the Mudkip. The larger Mudkip jumps in the water to rescue a baby that was being washed away, only to get caught in the current itself. It clings to a rock on the side of the water fall and finally agrees to let Brock rescue it.
Team Rocket arrives again, this time in a robot with scoops for hands, which they use to capture the baby Mudkip. Brock tells Lotad and Mudkip to use Water Gun at the base of the robot, which creates a mud pit and sinks Team Rocket. Pikachu then sends Team Rocket on their way. The show ends with the large Mudkip deciding to leave the lake with Brock.