Following his Manalo Conference victory, Ash returns home and enjoys breakfast with his Pokémon, Professor Kukui, and Professor Burnet. Suddenly, Naganadel senses something, and floats outside to see an open Ultra Wormhole overhead. Ash, Pikachu, and Rotom all realize that it is time for Naganadel to return home. Ash hugs Naganadel one more time and thanks it for its assistance, and, as a parting gift, Pikachu sends Naganadel off with a Thunderbolt. They then watch as Naganadel disappears into the wormhole, which closes in its wake.
Later, after school ends, Kukui asks his students about their holiday plans. Sophocles says he and his cousin Molayne will be traveling to Mossdeep City in Hoenn to visit the Mossdeep Space Center. Kiawe admits that he wants to battle Ash, as the pair didn't get to go up against each other during the Manalo Conference, and Ash accepts the challenge. Lana reveals that she will be assisting her father with his next ocean survey to find the Mythical Pokémon Manaphy. Still inspired by Oranguru's place, Mallow plans to turn Aina's Kitchen into a restaurant for both people and Pokémon. Meanwhile, Lillie hopes to finally awaken Magearna. Ash, however, admits he hasn't given any thought to his next goal. As he and Kukui walk towards home, Ash reveals that he is now unsure of his next move, now that he completed the island challenge. He turns to Kukui for advice, but is left dumbfounded when Kukui says that he just has to think about it himself.
The following day, Mallow hosts a tasting party at Aina's Kitchen, where she unveils her first-ever menu dedicated to Pokémon. While eating, Kiawe turns his attention to Ash, saying Olivia will be the referee for their match tomorrow. Sophocles asks Lillie about her progress with Magearna, but she admits her attempts so far have failed. Ash and the others urge Lillie to continue on, certain her observation and empathy will get through to Magearna. That night, while studying her father's notes on Magearna, Lillie hones in on Magearna's Soul-Heart component, giving it a zap of electricity and a polish in the hope of reawakening it, but to no avail. Lillie and Snowy eventually fall asleep beside Magearna. The next morning, they spot a drawing of Magearna together with Zoroark in Mohn's journal.
Meanwhile, Ash and Kiawe battle at the Ruins of Life on Akala Island. Kiawe's Charizard uses Fire Punch, knocking Ash's Lycanroc away. Ash orders Lycanroc to use Stone Edge, but Charizard flies upwards to avoid it before Kiawe calls for an Aerial Ace. As Charizard dives towards its opponent, Lycanroc runs up one of its Stone Edges and Bites down on Charizard's tail. Charizard uses Slash, sending Lycanroc to the ground. With both sides visibly exhausted, Ash and Kiawe use their Z-Moves, which are launched simultaneously, though Lycanroc's Splintered Stormshards proves to be more powerful and combines with Charizard's Inferno Overdrive. The flaming meteoric shower hits Charizard, knocking it down. Lycanroc sneers at its fallen foe, but it soon collapses from its own exhaustion.
Ash and Kiawe urge their Pokémon to get up, but neither of them responds. Olivia prepares to call the match a draw, when Lycanroc suddenly rises back up, thus giving Ash the victory. Kiawe accepts his defeat, recalling Charizard and thanking Ash for the match. Olivia is overwhelmed by their emotions and admits the battle was awesome. She then asks the boys about their next plans to become stronger. Ash admits he still has to figure it out, while Kiawe declares his intent is to complete his island challenge, master new kinds of Z-Moves, and become an island kahuna like his grandfather. Olivia tells Kiawe that he will need to know about the outside world for a broader perspective, as does Ash.
That evening, Gladion checks on Lillie as she continues to intensely focus on reawakening Magearna. Lillie apologizes for calling him over on such a short notice, admitting that she wanted to have Zoroark to meet Magearna. Gladion is perplexed by the request, and Lillie shows him the sketch of Zoroark and Magearna together, explaining that Zoroark must have seen their father conducting his research. Gladion complies, calling Zoroark out. When Zoroark emerges from its Dusk Ball, it is immediately overcome with familiarity if its surroundings and Magearna. Zoroark creates an illusion, showing Gladion and Lillie a flashback of Mohn working on Magearna, with an infant Lillie watching on. The illusionary baby Lillie even manages to learn to walk, overwhelming the illusionary Lusamine with joy as she enters the room. As Mohn asks Magearna to look after his daughter, Lillie is drawn to tears by the historic vision. Suddenly, a stream of purple lights beam from Magearna's Soul-Heart, blinding everyone in the room and inadvertently ending the illusion. As the light dies down, they see that Magearna is moving once again. Magearna bows to Lillie and presents her with a flower bouquet. Lillie accepts the bouquet and proceeds to hug her now-awakened friend. Gladion, Zoroark, and Snowy smile at the touching scene.
Meanwhile, Ash stares at the full moon through his bedroom window, recalling Olivia's earlier advice on knowing the outside world. Filled with inspiration, he abruptly leaps from his bedsheets, disturbing Pikachu and Rotom's sleep. Ash declares that he and Pikachu will return to Pallet Town again before beginning their next quest, to travel the world, to which Pikachu happily complies.