As Ash and his friends head to Grand Spectrala Island, they soon find themselves in a large area of fog, which starts to envelop the ship. From the fog, a massive shadow appears out nowhere and looms over the vessel, scaring them. Everyone hits the deck expecting to collide with the shadow, but nothing seems to happen. When they get up, the shadow has vanished and the fog fades away.Porter arrives on deck, and the group asks him if he saw the shadow, but he confirms that neither he nor the crew has seen anything. Despite this, everyone is certain that they did witness something. Meanwhile, a shadowed figure wearing a hat and trench coat listens in on their conversation.
The ship docks at Grand Spectrala Island, where Porter bids the gang farewell. At the same time, Team Rocket spies on the twerps aboard their submarine and plan to steal Pikachu as usual. At a local restaurant, the group asks if anyone's around, only for a big silhouetted figure to walk out from the back. Ash screams that a Snorlax has appeared, but it turns out to be the human owner of the establishment who merely looks like a Snorlax. The gang asks the owner about the giant Pokémon they saw, but the owner admits that he's never heard of any such Pokémon on the island. He does, however, reveal that a smaller island nearby is rumored to be the home of giant Pokémon. In his hurry, Ash runs down the road supposed to lead to the island, leaving Iris and Cilan in pursuit of him (the latter picks up a local guide and map as he leaves). Sighing, the owner remarks that he wasn't able to finish his explanation; the bridge leading to the island has long since been torn down, and the rumors dated back ten years ago.
At the bridge, the gang is dismayed to find the bridge torn down. Cilan confirms from the guidebook that the smaller island is a protected Pokémon sanctuary, which means Trainers probably don't go there often. Just then, the tide goes out to reveal a strip of land leading to the island. Cilan reads from his guide that the surrounding tides can change dramatically, and Iris is glad that they arrived just in time. While the group runs across the natural bridge, Team Rocket watches them from the water in wetsuits.
Reaching the smaller island, the gang walks into the forest just as a thick fog blankets the island. Iris is worried about the harshly reduced vision, while Cilan is intrigued by the mysteriousness of their location. Pikachu, sensing something, jumps off Ash's shoulder and starts calling out into the forest. This prompts massive footsteps to echo throughout the forest, and to everyone's shock and horror, a giant Heatmor rises from the trees! Heatmor breathes out a massive Flamethrower that sets the forest on fire, causing the local Pokémon to panic. A wild Foongus bumps into Iris's Axew as it tries to escape, and releases a cloud of Spore at Axew in its agitation, causing him to fall asleep. With Axew out of commission the group is forced to run for their lives, but end up at a cliff's edge instead. Ash has Pikachu attack Heatmor, but Heatmor merely shrugs off all attacks levied at it. Heatmor launches another Flamethrower that nearly throws Pikachu off the cliff, who Ash catches just in time. Before Heatmor can attack again, however, the figure from the ship jumps in front of Ash and company, raising their arms to stop Heatmor's advance. Heatmor stops, and vanishes in a brief cloud of fog, along with the mysterious figure. Cilan wonders if they've imagined everything that's happened since there's no longer any forest fire, but Iris points out that Axew is still asleep. It becomes clear that Axew needs medical attention and fast.
Separately, Jessie and James wonder about the fog, looking for the twerps. They briefly lose sight of Meowth, and seeing a Meowth shadow ahead think it's him, only for the real deal to pipe up below them, having caught up. The Meowth shadow turns out to be a giant Meowth that chases them through the forest, scaring them. At the edge of another cliff, the giant Meowth ends up blasting Team Rocket off the cliff side and into the ocean.
Trying to find their way back to the mainland, Ash's group finds themselves lost. Iris suddenly spots a Pokémon Center ahead. Ash is confused as to why a desolate island would have a Center in the first place, and Cilan points out that this Center looks extremely run down, but Iris is adamant that they visit. Inside, the Center is as dilapidated as it is on the outside, and the counter is swarmed by a group of wild Pokémon. Startled by the intrusion, they all flee in a panic. Placing the sleeping Axew on the counter, Iris calls for Audino, who eagerly appears. Iris explains that Axew needs help, and Audino runs off to get Nurse Joy. Nurse Joy appears, and after inspecting Axew says she'll prepare some medicine for Axew, before returning to the back room. Audino reappears with a mortar and pestle, confusing the gang who were expecting Nurse Joy. At this, Audino panics a little, running back so Nurse Joy can reappear, who merely confirms that she'll be preparing the medicine before retreating. Audino appears with a bunch of Berries in its arms, but is startled by the gang again and runs back, leaving Nurse Joy to reappear with the Berries in her arms instead. Nurse Joy tries to reassure Iris, but goofs up a little and speaks in Audino's voice instead! This prompts Ash to ask where Audino is, leading to a chain of disappearing and reappearing of Audino and Nurse Joy, who don't seem to be able to both show up together in one place. Eventually, Nurse Joy tiredly says that Audino is busy handling other duties in the back, and she'll be making Axew's medicine. As she grinds up a Chesto Berry and Sitrus Berry with some Oran Berries, Cilan notes how old-fashioned the medicine seems to be. Shortly afterwards, Nurse Joy finishes the medicine which Iris feeds to Axew, waking him up and re-energizing him. Ash and Cilan admit that they were initially concerned that Nurse Joy didn't seem to know what she was doing, but are glad that things seem to have worked out in the end.
Just then, the strange person appears at the door of the Center, revealing herself to be an older Nurse Joy tasked with the special duty of investigating established Pokémon Centers. She explains that she'd been receiving reports of a Pokémon Center operating illegally on the island, which is why she was deployed to investigate. Pointing at the other Nurse Joy, she confirms that the "Nurse Joy" is an impostor, and demands an explanation. Silently, the fake Nurse Joy takes on glittering golden aura that nearly blinds everyone, which starts casting an illusion.
In the illusion, the Pokémon Center is good as new, and is staffed by Audino and Nurse Joy. The older Nurse Joy realizes that the Nurse Joy in the illusion was her from over ten years ago, and that they're witnessing an illusion of the past when she used to work on the island. The Nurse Joy in the past carries in a crying Zorua which Cilan notes. Nurse Joy explains that in the past, she found a Zorua that had been injured by a hunter's trap, so she had nursed it back to health before releasing it. Since then Zorua made frequent visits to the Center to help out, finding Berries and even making remedies just like Nurse Joy did. Cilan recalls that Zorua has the ability to alter its appearance, and Iris concludes that the impostor Nurse Joy must really be Zorua! Tearfully, Zorua as Nurse Joy asks why Nurse Joy had to leave. Nurse Joy admits that when Trainers stopped visiting the island Center, she was ordered by headquarters to shut the Center down - she had wanted to tell Zorua, but Zorua had stopped coming around for some reason.
The fake Nurse Joy creates another illusory flashback, revealing that close to the time when the Center had shut down, it had been staying in the forest to prepare for its coming evolution into Zoroark. Not long after, it witnessed two Pokémon poachers kidnapping a pair of wild Ducklett, enraging it and forcing it to use its giant Heatmor illusion to scare the hunters away. Nurse Joy confirms that when the hunters were arrested, they tried to speak about the giant Heatmor sighting - and all this had taken place ten years ago. Zoroark had used its illusions to protect the island, and also created the gigantic shadow that Ash and the others had seen from the ship after sensing her presence.
Nurse Joy apologizes to Zoroark for not telling it of her departure, but asks Zoroark to cease its operations; illegally operating a Pokémon Center is a serious offense. Zoroark, still in its illusion of Nurse Joy, stands silent and sad. Iris exclaims that Zoroark wasn't playing the part of Nurse Joy as a prank, but was being a fully competent Nurse Joy in its own right, since it healed Axew with its remedy. Cilan guesses that the wild Pokémon they saw earlier must have been in the Pokémon Center to receive medical attention as well. The gang beg Nurse Joy to keep the Pokémon Center open for wild Pokémon instead of closing it. Nurse Joy, realizing that Zoroark merely wants to help out, praises Zoroark for its efforts and agrees to stay with Zoroark to keep the Center available for wild Pokémon. Zoroark lifts its illusion and has a tearful reunion with its friend, while the gang decide to help clean up the old Pokémon Center. By evening, the Pokémon Center is good as new, and Zoroark and Nurse Joy promise to keep everything running smoothly. The next day, Ash and friends leave on the next ferry and wave goodbye to Nurse Joy and Zoroark, as their journey continues.
TRIVIA
- Professor Oak's Pokémon Live Caster: Haxorus
- Music from Pokémon the Movie: Black—Victini and Reshiram and Pokémon the Movie: White—Victini and Zekrom is used in this episode.
- As of this episode, Klang is the only non-legendary Generation V Pokémon yet to be seen in the anime series.
- This episode marks the debut of Team Rocket's Basculin submarine.
- The scene in which the tide changes and allows Ash and his friends to move on to the next island is similar to a scene in The Crystal Onix.
- Ash and Professor Oak narrate the preview for the next episode.
- Let's Join Hands is altered to include live-action shots of Shiritsu Ebisu Chūgaku in order to promote the upcoming short Pikachu and Eevee Friends.
- Towards the end of the episode, Ash and his friends are waving goodbye to Nurse Joy and Zoroark from the cruise ship railing near the chimney. However, when the scene changes to a full view of cruise ship, none of them are visible.
- In one of the scenes where "Audino" goes to fetch the fake Nurse Joy, one of it's feelers are colored pink instead of cream.
