Upon arriving at a city, Ash and his friends see something poking out of a bush and identify it as a baby Stantler. Ash looks it up on his Pokédex while Brock attempts to lure it out by mimicking classic Stantler behaviors, and then by offering it food. However, Stantler remains hesitant and produces a nice scent from its antlers. A herd of Stantler suddenly charges at the trio, forcing them to flee. Once they are gone, the baby Stantler retreats into the bushes. The trio starts searching for the Stantler after Brock noticed its leg was injured. Officer Jenny approaches them and takes them back to her office to file a report. She informs them that the Stantler herd has been terrorizing the town. However, Brock is skeptical and suggests there must be more to them than meets the eye.
Just then, they find Team Rocket being chased. After performing their motto, they explain they were attempting to capture all of the city park's Stantler, but were forced to abandon their plan after being chased by a herd of them. Suddenly, a sweet smell wafts over everyone, and a herd of Stantler runs into town. Team Rocket flees, while Jenny ushers Ash and Misty into the police station for safety. Brock remains outside and witnesses the Stantler seemingly running through light poles and walls. Ash urges Brock to run, but Brock waits for the herd to hit him. However, the herd of Stantler goes right through him, and Ash and Misty are amazed as the illusions begin to fade.
Brock approaches the baby Stantler and says he could heal its wound. He goes inside the police station and bandages Stantler's front leg. Ash, Misty, and Jenny ask how he found this out; Brock replies that he noticed that the Stantler were going right through buildings. Once he is finished, Stantler looks at Brock admiringly and then falls asleep on his lap. Ash asks Brock if he wants to catch Stantler, but Brock thinks it is best if it goes home. Team Rocket listens in through a periscope, and Meowth is frustrated that there is only one Stantler. James, however, comes up with a new plan, and uses the trio's remaining funds to get it. While Jessie and Meowth are initially angered, James convinces them that the money will not be important if they do not have anything to give to Giovanni.
The next day, Brock releases Stantler into the forest. However, Stantler is hesitant, and nudges Brock to show its affection. Brock steps back and yells at Stantler to leave; the Big Horn Pokémon sadly does so. Meanwhile, Team Rocket spots Stantler from their Meowth balloon. As Ash and his friends return to the city, Brock turns back and is shocked to see Team Rocket's balloon in the distance. With the help of James's Anti-Stantler number 7, Team Rocket catches the baby Stantler to give to Giovanni. The trio floats down to grab their catch, but Meowth becomes teary-eyed from Stantler's cries. Brock confronts the trio, but James presses a red button, and the Anti-Stantler 7 shoots out spears that stop Brock from passing through, allowing Team Rocket to escape. However, Brock sends out Onix to destroy the mecha and then chases Team Rocket's balloon. Hearing Stantler's cries, Ash orders Pikachu to use Thunderbolt on Team Rocket, but it misses because the balloon is too high up. Just then, a real adult Stantler leaps from a mountain ledge, cuts through the hot air balloon, and cuts the rope holding the baby Stantler. Ash calls out Bulbasaur to use Vine Whip to catch the net, but Stantler falls out. Brock then rushes in and catches it in time.
Team Rocket crash-lands in the forest, and their balloon becomes entangled in the trees. The trio is then confronted by a herd of Stantler. Thinking it is another illusion, James throws the remote at one, which bounces off its head. The Stantler then crushes the remote with its hoof and the whole herd stampedes Team Rocket, causing them to blast off. Meanwhile, Brock and his friends watch on as Stantler returns to its family, and the reunited herd treks back to their mountain home.