Dawn and her friends are passing through a town on their way to the Celestic Contest when they see Zoey in the middle of a tough battle with a well-dressed Coordinator. Zoey's Glameow is beaten by her opponent's Mismagius, and this stranger introduces herself as Fantina—the Hearthome Gym Leader herself! She's traveling as a Pokémon Trainer to become a better Gym Leader and perfect her own style, so she's not interested when Ash requests a Gym battle and Jessie (disguised as the reporter Jessedia) requests some interview time. But Fantina is willing to battle Ash in a friendly three-on-three battle, starting with her Drifloon against Ash's Buizel.
The battle's barely started when Drifloon hits Buizel with Hypnosis, putting it to sleep. By the time Buizel finally wakes up, it's too exhausted to battle! Next up is Chimchar, but Drifloon uses Psychic to stop Chimchar's Flamethrower and follows up with Hypnosis yet again. Now Chimchar falls sleep, too! Now it's up to good ol' Pikachu to save the day—if it can. Pikachu confidently launches a Volt Tackle that's slowed to a crawl and then reversed by Drifloon's Ominous Wind. Pikachu strikes back with Thunderbolt, but that just sparks Drifloon's Evolution into Drifblim!
Drifblim uses its aerial mobility to dodge Pikachu's Thunderbolt, then uses Hypnosis again! With Pikachu sleeping like a baby, Ash's team is unable to battle. Ash is bummed by the loss, but Fantina promises him a battle at the Hearthome Gym and even agrees to someday battle Dawn as well. That night, Jessie, hoping Yanmega can learn Drifblim's moves, shows her Pokémon the videos of Fantina's battle, while Zoey shows Dawn her third Ribbon. Now that Fantina has given them some new challenges to consider, Dawn and Ash are ready to get back on the road to Celestic Town!
While passing through a small town, Ash and his friends stop to watch Zoey battle an unfamiliar Trainer, who is actually the Hearthome Gym Leader Fantina. Glameow attempts to dodge a Mismagius's Psybeam, but gets hit and confused. Zoey orders a Shock Wave, but since Glameow is confused it misses. Glameow recovers and fires off another Shock Wave, but it is blocked by a Magical Leaf from Mismagius, and then the whole lot is sent back at Glameow with a Psywave. The combination knocks out Glameow, and the two battlers exchange compliments. As they shake hands, Brock butts in and professes his love for the other Trainer; however Croagunk stops him. Zoey introduces them to Fantina, informing Ash that she is the Hearthome Gym Leader as well as a Top Coordinator. Fantina mentions that she has become a traveling Trainer, and so had no choice but to leave the Gym empty while she is away.
Team Rocket, who have been listening in, discuss Fantina. James mentions that the "job description" reminds him of another Gym Leader. Jessie decides that they need to figure out Fantina's style so she can copy it to win Contests.
In the nearby Pokémon Center Ash tries to persuade Fantina to go back to the Gym so that he can challenge her. Jessie, disguised as reporter Jessadia and flanked by her teammates as the camera crew, then butts in and tries to get Fantina to talk about her role as a Gym Leader, but Fantina brushes them off, saying that she needs to go and train. Zoey suggests that they will understand better if Fantina tells them why she became a traveling Trainer. Fantina explains that with a lot of hard work, she was able to win the Grand Festival with her Misdreavus, earning the title of Top Coordinator. Afterwards, she was invited to become a Gym Leader, and the Hearthome Gym was opened. However eventually some of the Trainers would defeat her in a rematch, and she felt that she wasn't giving them a good enough battle. Brock states that he understands exactly how she feels from when he was the Pewter City Gym Leader. Fantina also states that she has been working on a new battle style which incorporates the beauty of a Contest Battle and the ferocity of a Gym match. She agrees to a battle, as one of the first things that traveling Trainers do. However her Pokémon are too tired for two battles, so Ash and Dawn use the Coin Toss app on her Pokétch.
Dawn is fuming that she lost the Coin Toss as Ash and Fantina get ready for battle. Ash suggests that the battle should be three-on-three with substitutions, over when all the Pokémon on one team are unable to battle. Fantina agrees and Dawn uses a Coin Toss to decide who should start the battle. Fantina wins the toss and goes first, while Jessie tells James to only focus the camera on Fantina. After Fantina holds up a Poké Ball, Ash sends out Buizel and Fantina sends out her Drifloon. Drifloon whips up an Ominous Wind. Buizel counters with Water Gun, but Drifloon dodges and hits Buizel. Buizel breaks out of the attack and hits Drifloon with Aqua Jet. Drifloon puts Buizel to sleep with Hypnosis, before winching him up into the sky, following up with Psychic. Buizel wakes up, but then promptly faints. Ash sends out Chimchar, who opens with a Flamethrower, but Drifloon stops it with Psychic and plays around with it before using Will-O-Wisp and following up with Hypnosis. Chimchar struggles to stay awake, but falls asleep. Ash immediately recalls Chimchar and Dawn comments that it was good that Ash got Chimchar back in its Poké Ball, but Brock points out that unlike confusion, Pokémon continue to sleep even after they are returned to their Poké Ball.
Ash sends out Pikachu, knowing that if Pikachu falls asleep the battle is as good as over. Drifloon hits Pikachu with Will-O-Wisp and Pikachu retaliates with Thunderbolt, hitting Drifloon. Pikachu leaps into a Volt Tackle, but Drifloon blocks his advance and pushes him backwards with Ominous Wind. Ash calls for another Thunderbolt. It hits, but doesn't help as it simply causes Drifloon to evolve into Drifblim. Dawn checks it on her Pokédex, then Pikachu uses Thunderbolt but Drifblim dodges. Fantina has her Pokémon move into close range and put Pikachu to sleep with Hypnosis. Ash forfeits the match, and the Trainers exchange compliments. Fantina says that she will return to the Hearthome Gym to do a bit of work with her Drifblim, agreeing to have a battle with Ash when he gets there. Dawn also asks for a match sometime, and Fantina agrees to it.
That night, Team Rocket show the footage of the battle to Yanmega and Jessie asks it to dodge like Drifblim, but Yanmega says that it can't. James and Meowth point out that Yanmega and Drifloon are very different Pokémon, but Jessie remarks that some special training will help.
Back at the Pokémon Center, Zoey shows Dawn that she has won her third Ribbon. She says that she won't be entering the Celestic Town Contest, but will be there to cheer Dawn on. Meanwhile, Ash is sitting on the floor surrounded by his Pokémon as he tries to figure out a way to counter Drifblim's Hypnosis. Dawn is equally determined to win her upcoming Contest, as she and Ash proclaim that some more training is in order.