Ash and co. are still in the forest, but they are lost. Max is blaming it all on May because she wanted to take another direction. May insists that the path they are now on is prettier and had more beauty. Then she blames Max for not paying attention to his Pokenav. Max shouts out to her that his Pokenav is out of range, therefore it won't work. Brock pushes both of them away and tells them not to fight. He says that Ash and him used to always get lost. Ash agrees with Brock. May and Max are still angry with each other. Suddenly, Ash sees something move in a tree. A Treecko appears on the branch. Ash looks up Treecko in his Pokédex. A bunch of more Treecko appear from the tree. Ash is happy that he found a Treecko because he has always wanted one. Ash throws a Pokéball at one of the Treecko, but Treecko knocks it right back at Ash. May tells Ash that he has to weaken the Pokémon first. She is surprised that Ash didn't know that himself. Ash sighs. The Treecko starts to get away, so Ash runs after it. Everyone else follows him.

Ash sees a strange-looking tree ahead. He trips over a large branch on the ground and slides down a mini hill. Ash manages to get himself up and stares straight into the tall tree. This tree is much taller than any of the other trees in the forest. Ash discovers that the tree is dying. Suddenly, a twig is thrown right at him. Treecko, who is sitting on the tree, threw the twig at Ash. Ash shouts out to Treecko to come down and battle. Treecko jumps from branch to branch and lands safely on the ground. Treecko quickly strikes Pikachu with its tail. Pikachu is slammed into the tree. Pikachu gets up and tries to tackle Treecko, but Treecko is too fast for Pikachu. It hits Pikachu with its tail again. Team Rocket is watching the battle. They are impressed with Treecko's power. Meowth tells his friends that the boss will be happy with Treecko, and that they will be promoted to directors. Jessie and James also want to catch Treecko.

A group of other Treecko walk behind the Treecko that Pikachu fought. An older Treecko walks up to the Treecko that Pikachu fought and starts to talk to it. For some reason, the Treecko gets mad and knocks down the older Treecko. The older Treecko gets up and begins to talk to the younger Treecko again. Meowth translates what the Treecko are saying. The older Treecko is telling the other Treecko that their tree is dying and that they have to get rid of it. The younger Treecko is angry and tells the older one that he is staying to protect the tree. James and Meowth are touched by the younger Treecko's story. Jessie has different thoughts. She thinks that change is the best thing to do. Without change you won't make any progress ini life. Then Jessie says that she has a brilliant plan to capture all the Treecko. James and Meowth cheer for her.

The bunch of Treecko walk away with the younger Treecko remaining. Treecko looks at the old tree and jumps on it. It runs back into the forest. Pikachu gets an idea. It jumps on the tree and calls out for Ash. Ash understands Pikachu's plan. They decide to wait for Treecko beside the tree.

Meanwhile, Brock, May, and Max are eating lunch. Max is worried about Ash, but Brock tells him that Ash will be fine. Ash and Pikachu are sitting on a tree branch waiting for Treecko. Ash hopes that Brock, May, and Max aren't too worried about him. A flock of Murkrow fly in the sky. Ash suddenly gets an idea. He sends out Taillow and tells it to find Brock, May, and Max. He wants Taillow to lead them here while he waits for Treecko. Seconds later, Treecko walks up to the tree with a leaf full of water. It pours the water beside the tree and covers the spot with dry leaves. Then Treecko walks back into the forest to get some more water. Ash feels kind of sad for Treecko since it's doing everything it can to save the tree. Treecko covers the tree with more leaves. Ash decides to get down and help Treecko. Treecko gets angry at Ash, but Ash tells Treecko that he wants to help it save the tree. Treecko accepts Ash's kindness and calms down.

Suddenly, a vehicle comes up and steals all the Treecko. Ash spots the vehicle and tells it to stop. The vehicle tries to run Ash down. Then Team Rocket comes out of the vehicle and says their motto. The Treecko are put inside a cage. Team Rocket runs into their balloon, and they take off with the Treecko. Pikachu uses Thunderbolt on the balloon, but the attack doesn't work. James tells Ash that their balloon blocks off electricity. Ash is about to send Taillow out, but he remembers sending Taillow away to find his friends. Team Rocket takes out a net and uses it to capture Pikachu. Treecko gets angry and swings onto the trees. It tries to pop the balloon with its twig. Team Rocket laughs, and James sends out Cacnea. Cacnea uses Pin Missile at Treecko but misses. Since Ash never saw Cacnea before, he looks it up in his Pokédex. James tells Cacnea to defeat Treecko. Treecko climbs up a tree, jumps off it, and lands in Team Rocket's balloon. Jessie falls onto the side of the balloon. Unfortunately for her, she is bumped into a button that releases the top part of the cage that holds the Treecko. The Treecko run out of the cage. Team Rocket struggles with catching the younger Treecko. Treecko jumps onto the balloon. It sticks out its tongue at Cacnea. Cacnea gets mad and fires a Pin Missile at Treecko. Treecko dodges the attack, and the attack bursts open the balloon. Part of the net which is holding Pikachu breaks. Team Rocket blasts off into the sky.

Pikachu walks out of the net and is reunited with Ash again. Ash thanks the Treecko for saving Pikachu. Everyone heads back to the old tree. The older Treecko agrees to help the younger Treecko save the tree. Suddenly, the tree begins to split in two. All the Treecko do their best to put the two pieces of the tree back together. Ash goes into his backpack to fetch a rope. Then suddenly, the sun comes up. It shines on the tree. Ash is given a history on how the tree was born. Soon later, the tree finally splits into two pieces and falls to the ground. Ash bends down and tells Treecko that the tree appreciated everything it did to help it. Treecko is angry and hits Ash with its tail. Ash thinks that Treecko is ready to battle him. Meanwhile, Taillow has found Brock, May, and Max, and they are running towards Ash.

Pikachu starts the battle off with a Thunderbolt. Treecko dodges the attacks until it gets hit. Unfortunately, grass Pokémon can endure electric attacks easily. May notices the great speed that Treecko has. Ash orders Pikachu to use Quick Attack. Treecko jumps into the air, barely dodging the attack. While Treecko is in the air, Pikachu uses Thunderbolt. The attack does more damage than usual leaving Treecko helpless. Max is shocked that an electric attack was effective againt a grass type. Brock explains to them that in midair, electric attacks are more powerful. Ash throws a Pokéball at Treecko and captures it. Then Ash sends out Treecko. It agrees to travel along with Ash. The older Treecko gives Ash's Treecko a tree seed. Ash's Treecko takes the seed and buries it in the ground and covers it with leaves. Ash and co. wave goodbye to the Treecko, and they continue their journey to Rustboro City.