The episode begins with Team Rocket eating macarons present in a tree hollow, glad that they could find something to eat in the middle of nowhere and claiming that fate is keeping them well fed. Suddenly, they hear children laughter and notice a bunch of angry eyes. Team Rocket asks the culprit to come out and reveal themselves. The laughter is revealed to be coming from a group of angry Phantump (as revealed by James's handheld computer), one of them Shiny, angry at Team Rocket for eating their macarons. Jessie and James shrug them off, with Jessie picking up a macaron and claiming that they follow the principle of "finders keepers, losers weepers!". The Shiny Phantump flies towards Jessie to claim the macaron from her but she pushes it away. Angered, the Shiny Phantump uses Forest's Curse on Team Rocket to trap it; Jessie, however, refuses to let go, and proceeds to take another macaron. The Shiny Phantump proceeds to take it away from her as well, just as the other Phantump use Shadow Ball, causing Team Rocket and the Shiny Phantump to blast off, much to the shock of other Phantump. The Shiny Phantump manages to take away Jessie's macaron by tickling her in the nose, but Jessie pushes the Stump Pokémon in the other direction, effectively separating it from Team Rocket. Seeing it blast off, the other Phantump decide to search the area for their friend.
Ash and his friends are continuing towards Snowbelle City when Bonnie, Dedenne and Squishy notice something falling from the sky, which is revealed to be the Shiny Phantump. Phantump falls onto Ash, knocking both itself and Ash out. When Ash regains consciousness, he and his friends, particularly a curious Bonnie, notice Phantump gladly eating the macaron it had taken from Jessie. Clemont wonders if the Phantump fell off a tree, but Bonnie replies in the negative, claiming that it fell from the sky. Ash checks it with his Pokédex and notes that the Phantump is of a different color from the one in the Pokédex. Bonnie goes to greet Phantump but the Stump Pokémon gets startled and uses Forest's Curse, then flies away from the group. Ash asks Pikacku to use Iron Tail to free the group. Clemont states that according to the Pokédex, Phantump live in remote forests and so it is unusual for one to be living in a lush green one. Serena looks up in her guide book and informs the group about Phantump tendencies of getting strangers lost in woods by imitating children voices. Bonnie is excited and wants to hear Phantump make children noises but Serena is scared, claiming she does not want to get lost in the forest. Amidst all this confusion, Ash's stomach growls. Serena offers him some buns to eat but before he could take a bite, the bun is stolen by the Shiny Phantump, enraging Ash. The Shiny Phantump flies and eats it behind a tree, as Bonnie watches with deep admiration. Bonnie asks Serena for another bun to give it to the Phantump, who snatches it off her hand and eats it well. Bonnie asks Phantump about its friends, which causes it to panic. Ash and his friends deduce that the Phantump is lost and decide to help it. Serena looks up in her guide book and finds a big tree atop the mountain: an area where long ago, people would often get lost by children's voices. So, the people began leaving treats for Phantump to avoid being led astray by the voices, a practice people follow in the present as well. Seeing its home on Serena's guide book, Phantump gets happy and the group sets off to take it to its home.
On their way to the mountain top, the group runs into a Diglett, scaring Phantump, who hides behind Bonnie for protection as two more Diglett and two Dugtrio appear on the site. Ash and Serena try to calm the Phantump down, stating that they are just friends and want to say hello. The Diglett and Dugtrio go back, and Phantump heaves a sigh of relief. Clemont states that this might be the first time that Phantump has met Diglett and Dugtrio and possibly the first time it has been away from home; Bonnie puts this as the reason for Phantump panicking on meeting the group. Ash tells Phantump about the variety of Pokémon in the Pokémon World, surprising Phantump, and Bonnie urges it to meet new Pokémon and make new friends. Phantump gets excited at this prospect and starts flying along the route to the mountain top, being followed by the group.
The group reaches a cliff and a tired Clemont suggests taking a break. Bonnie lets Squishy out of her satchel for photosynthesis. Phantump gets scared of the Order Pokémon, but manages to subdue its fears. Serena offers some home-made macarons to the group, alerting Phantump as well as Chespin, who comes out of its Poké Ball and proceeds to eat all the macarons by itself. A curious Phantump stares at Chespin and Chespin offers a macaron to the Phantump. This causes Phantump to cry as it remembers its friends sharing macarons with it. Bonnie tries to console the Phantump, asking it to eat together with the group. Clemont claims that the Phantump must be feeling homesick and Ash assures it that they shall take it back to its friends before it even knows. While eating, the group encounters a wild Helioptile, startling Phantump. Dedenne offers a macaron to the Generator Pokémon and plays with it and Pikachu for a while. Bonnie helps Phantump make friends with the Helioptile; when it does, it flies off in excitement and greets a wild Bidoof. The group praises Phantump for its efforts as Team Rocket watches the entire scene. James claims that Forest's Curse is a treacherous move and that they must separate Phantump and Pikachu before capturing the latter. Jessie, however, seems unconcerned and believes a bit of acting is what they need.
Continuing to the mountain top, the group runs into Team Rocket disguised as the entire Ralts evolutionary family. Team Rocket members go to the Phantump to play with it and start running away with the Phantump; the group decides to follow them to catch up. Team Rocket reaches the end of a cliff and falls, while a seemingly delighted Phantump flies back to Bonnie, who is upset that she could not play with the Psychic-type Pokémon. Concurrently, the Phantump group is still looking for its friend. Team Rocket comes in disguised as (large) Phantump next; An overjoyed Phantump flies towards the other Phantump to greet them but halts, sensing something suspicious. Team Rocket manages to grab the Phantump, and runs off, trailed by the group. An excited Ash separates from the group in search of the Phantump, and notices Jessie (still disguised as Phantump) playing with the Shiny Phantump, which is actually a fake. On the other hand, James and Meowth's disguises are busted by Serena, Clemont and Bonnie, who sensed trouble by seeing the macaron Phantump was holding, dropped on the ground and have been searching for it since then. James inflates the balloon on Phantump's trap box and sets it in the air and then flees with Meowth. Serena and Clemont decide to rescue the Shiny Phantump, but the Shiny Stump Pokémon is instead rescued by its friends using Forest's Curse. Serena wonders if the Phantump flew all the way to find the Shiny Phantump, who is very glad to have reunited with its friends.
Meanwhile, Jessie is still being trailed by Ash, but stops and throws a few Phantump-shaped bombs at him, and a Phantump-shaped trap to capture Pikachu. Jessie reveals her disguise and reunites with James and Meowth. Team Rocket recites its motto, and Ash commands his Pikachu to use Thunderbolt to break free of its trap, to no effect. As Team Rocket tries to flee on their balloon, it hears children laughter. Meowth knows just where it might be coming from: the Phantump. Ash catches up with Serena, Clemont and Bonnie, who tell him about the Phantump reunion. The Phantump use Energy Ball to pop the balloon, and the fall breaks open Pikachu's trap. Not giving up, Jessie and James send out Gourgeist and Inkay respectively, to use Dark Pulse and Psybeam on the Phantump. The Stump Pokémon counter by using Horn Leech and then use Forest's Curse to trap Team Rocket; Pikachu's Thunderbolt blasts off Team Rocket again.
The group finally reaches the mountain top and Serena and Clemont present the Phantump with macarons and Pokémon food, much to their joy. Bonnie advises Phantump to take care of itself and not to get lost again. The Pokémon, the Shiny Phantump had made friends with, come to visit the Phantump. The Shiny Phantump happily greets its new friends and introduces them to the other Phantump. The group then bids farewell to the Shiny Phantump and its friends and set off to Snowbelle City.
Meanwhile, a starving Team Rocket is looking for food. However, no sooner that they hear children laughter, they rush off in abject horror, not bothering to turn around and learn that the laughter is just coming from two Campers.