Template:Incomplete synopsis
On the way to Fallarbor Town for May's next Pokémon Contest, a Zangoose runs up to them. Then, a bigger Zangoose appears. It starts to talk and realizes that it is their old friend, Nicholai. They have a picnic, and Nicolai tells them that he went to the Petalburg Gym. May asks Nicolai if he saw their dad. Nicholai explains that after he told Norman and Caroline that he is a friend of May and Max, they invited him for dinner and accepted his gym challenge. But he explains that he lost. He says that Norman must have wore short shorts during training. Then, May and Max get so angry and scold him. Nicolai pats May on the back. Then, Nicolai tells them that he wants to get stronger, and Ash challenges him to a battle refereed by Brock.
The battle begins and Nicholai gets into a Marshtomp costume, and sends out Marshtomp. Apparently his Mudkip evolved. Ash chooses Treecko. Nicolai tells Marshtomp to use Water Gun, but Ash has Treecko dodge it and use Quick Attack. Then, Marshtomp follows Treecko while using Water Gun. It stops Treecko from his Quick Attack. Then, Marshtomp uses Mud Shot, knocking him down. But Treecko manages to get up. Nicolai tells Marshtomp to use Iron Tail, but it manages to get up and use Bullet Seed. It hits Marshtomp and knocks it down with Pound.
Meanwhile, Team Rocket watching the battle from behind the bushes, and plot to steal Pikachu during the battle. Jessie sends out Seviper to have it capture Pikachu.
Back on the battlefield, Nicolai takes off his Marshtomp costume and replaces with the Zangoose costume. Then, he sends out his Zangoose. Nicolai tells Zangoose to use Swords Dance, but as it starts to use it, it stops. Nicolai asks what is wrong, but Zangoose just walks away, and disappears into the bushes. After a while, Team Rocket run out of the bushes screaming, and Zangoose and Seviper fly out, glaring at each other in anger. Ash asks Team Rocket what they are doing there, after saying the first sentence of their motto, Zangoose and Seviper roar fiercely. Max explains that Zangoose and Seviper are arch enemies. Brock says that they will start to fight and not give up.
After tackling each other, they look at each other. Meowth jumps in and tells Seviper to forget about Zangoose and to capture Pikachu together but he only succeeds in being whacked with Seviper's tail. Meowth is sent rolling down the hill with Team Rocket and falling into the river.
Seviper wraps Zangoose, and Zangoose bites Seviper. Nicholai tells Zangoose to stop but is knocked over by the two Pokémon. The two Pokémon fall in the river. Flowing down the stream, Seviper uses Poison Tail and Zangoose hits a rock, unconscious. Just as it is about to attack Zangoose again, Ash sends out Corphish, it uses BubbleBeam to attack Seviper, and carries Zangoose to shore. Zangoose seems to be hurt really badly. Then, Brock explains that he will help to heal it.
After mixing the medicine, he passes it to Nicholai. He feeds Zangoose the medicine. Max says that Zangoose will not stop.
As Team Rocket sit near the river, Seviper suddenly jumps out of the river and lands near them. Without thinking, James yells at it and wants Seviper to apologize. Just then, James immediately apologizes as he notices Seviper’s anger. He kneels and pleads for forgiveness and Seviper decides to forgive him. Then, Meowth asks Seviper if he is finding Nicolai’s Zangoose, and he nods. Then, Meowth says that Seviper still wants to battle Zangoose. Jessie chimes in and says that there IS a fierce hatred in the world, just like her hatred towards Cassidy. If she see Cassidy, she wants to kill her. So Jessie, being sympathetic, decides to take Seviper’s side and help find and defeat Zangoose.
Back to the other side, Ash and Nicolai do some Pokédex research for info. on Seviper. Then, they decide to try it themselves. Nicolai gets into a Zangoose costume, and Ash gets into a Seviper costume. Then, they start to run at each other, and Seviper uses its tail to knock Zangoose down. Nicolai cries out in pain, Ash then realizes Seviper’s strength. Zangoose gets up. Seviper is about to use its tail again, but Zangoose dodges it. Then, Seviper bites Zangoose. To Be Continued