As Ash, Misty and Brock are walking along the path, they notice that the whole forest is green except for a couple of trees that are totally bare. Brock mentions that the trees do not seem to be burnt and it is not fall yet and begins to think something is amiss. Further down, Ash sees a group of Heracross eating sap out of a tree. Using his Pokedex, Ash learns that Heracross possesses great strength and power and loves to eat sap, and as such, decides to capture them.
Out of nowhere, a stranger emerges from the forest and introduces himself as Woodruff, a Pokémon ranger. Woodruff, although not stopping Ash from catching the Heracross, warns him that if he were to proceed, he would cause a great deal of damage. Ash, a little confused, thought he would be doing the forest a favour as the Heracross are sucking all the sap from the trees and are destroying the forest. A flock of Butterfree then appear to join the Heracross in eating the sap from the trees. Apparently, the Butterfree rely on the Heracross to penetrate the tree to release the sap. The Butterfree then eat whatever Heracross leaves. Ash then realises that by catching the Heracross he would destroy Butterfree’s food source. A little mystified our heroes wonder what is destroying the forest. Woodruff says that the balance has been destroyed by a group of invaders. Just as Woodruff finishes, Pikachu senses something and a large number of Pinsirs emerge from the forest.
The invaders scare off the Butterfree and begin to eat the sap. Ash and Misty try and convince the Heracross to fight, and it seems like their speech had worked as the Heracross begin to fly at the invaders. The Pinsir respond by moving their spiked horns and looking really mean. The Heracross, frightened, quickly fly off in the opposite direction. Woodruff explains that although they could win, they are peaceful and friendly and prefer to just fly away. Our heroes then notice that there still remains one Heracross that appears to be protecting a Butterfree. Ash calls upon Bulbasaur who uses his vine whip attack to knock the Pinsirs off the tree. Although vine whip was successful, the Pinsirs recover quickly and jump back onto the tree. Pikachu then uses his thunderbolt attack and the Pinsirs then attack our friends. Pikachu uses his thunder attack again and the Pinsirs flee back into the dense forest. Heracross then tries to suck the pollen out of Bulbasaur’s bulb (this is very funny). Bulbasaur, using his vine whip, sends Heracross flying.
Woodruff says that the Pinsir live on the other side of the river in another forest. Why they are coming here remains a mystery. Misty then mentions that they should go (remember Misty finds bug Pokémon “creepy”) but Brock and Ash want to help. So our friends head off towards the Pinsir’s forest and it appears as though Heracross has decided to tag along. Upon arriving at a deep canyon separating the two forests, Woodruff leads them to a bridge, which appears to have been destroyed. While our friends figure out a way to cross the canyon, Heracross appears and pushes over a large tree to create a path across the canyon. Our friends continue their journey into the forest and Woodruff leads them to the largest tree – Pinsir’s home. At the top of the tree Ash notices an extremely large Pinsir. Woodruff realises that it is not a Pinsir but rather a robot Pinsir, as there are two large tanks on its back. Team Rocket then emerge and launch into their infamous motto. Meowth explains that as they were walking through the forest, starving, he smelt something sweet (even though he has no nose). Jessie and James follow Meowth to the source of the sweet odour, which just happens to be sap coming out of a tree. Meowth tastes it and finds that he likes it. Jessie and James try as well as they too are starving and they also find the taste to their liking. Team Rocket decides to suck all the sap out of all the trees, bottle it and sell it at supermarkets, making them filthy rich.
Realising that Team Rocket is destroying the balance of nature, Ash gets into his fighting pose. Jessie and James call upon Lickitung and Victreebel but neither of them wishes to fight but rather eat the sap coming from the tree. James actually ran and hid in the forest thinking that once releasing Victreebel it would attack him (very funny). Meowth attacks with his robot Pinsir, which is controlled via a remote control. Bulbasaur attacks with razor leaf but it is ineffective against Pinsir’s steel body. Bulbasaur tries vine whip and sends the robot Pinsir into a spin. Pikachu then uses thunderbolt but the robot Pinsir uses the electric shock to recharge its batteries and shock our friends. Ash, Mist and Brock appear to be in trouble as the robot Pinsir is about to crush them. However, Heracross stops the robot Pinsir, but it fights back by pushing Heracross backwards. Meanwhile, our friends have recovered and Ash and Misty cheer on Heracross. While Heracross and the robot Pinsir continue to battle, Ash and Woodruff remove the two large tanks from Pinsir’s back. Team Rocket then fight over the remote control, destroying it (as they usually do). Heracross lifts the robot Pinsir into the air and tosses him straight up … to everyone’s amazement. The robot Pinsir lands on Team Rocket and explodes, sending Team Rocket flying.
Now that the robot Pinsir has been destroyed, the Pinsirs return to their home and the balance is restored. Brock, Misty and Ash say their goodbyes to their new friends and upon heading towards Violet city, Pikachu notices that Heracross is still following them. It appears as though Heracross wants to join our heroes, so Ash catches Heracross and says “Heracross chose me”.
Narrator: Now Ash, Misty and Brock continue their journey with a new addition to their circle of very special friends