Ash, his classmates, and their Pokémon are camping in a forest. Ash, Kiawe, and Sophocles are helping to set up a tent, Mallow and Steenee are preparing food, while Lillie is trying to set a campfire to cook the food. Litten comes over to her and helps light the fire, only for Snowy to end up freezing the fire with Powder Snow. Ash calls out, pleased that the tents are now set up, and Mallow informs the others that the curry is almost ready.
Then suddenly from behind, Lana, illuminating her face with a flashlight, begins to tell them about the scary history of the forest. She tells them that when people enter the forest, they tend to fall asleep for no good reason and without any idea that it is happening. When they awake, Lana tells them they are just skin and bones like they haven't eaten in ages. Mallow says that it is just one of Lana's jokes, but a rustling sound ends up scaring Mallow and Lillie, only for it to be revealed as Rockruff. Ash tells Rockruff not to scare them like that, unaware that across the river, a Morelull is watching them.
Soon the curry is ready and everyone is eating their meal. Kiawe notices there is still a lot left and Lillie explains that she hadn't been aware that rice expands when cooked. As the group discuss what they might do in the evening, Mallow notes it will get dark at night and asks Sophocles if he will be alright. In response, Sophocles brings out a Lampent-shaped lamp and calls out his Charjabug to power it up.
Nesting on a tree branch, Rowlet has a cookie in its mouth which it drops into the bushes. Rowlet wonders where it had disappeared before flying off in another direction, as Morelull peeps out from behind the bushes. Meanwhile, Sophocles is lounging on a sun-lounger, and Mallow and Steenee are picking berries from the trees for dessert. Elsewhere, Kiawe and Ash are battling each other with Pikachu and Turtonator. Ash has Pikachu attack with Quick Attack but Kiawe has Turtonator stand its ground and take the attack. Litten then senses something in the bushes, which grabs Rotom's attention as well. Just then, Rockruff jumps out of the bushes, scaring Rotom.
Meanwhile, Mallow is still picking Berries from the trees when she notices that Steenee has disappeared, the Berries it was holding now on the floor. Later, Ash and Kiawe also notice that the others haven't returned and wonder where they had gone to. Pikachu then senses something nearby, and though Rotom guesses it is Rockruff, Pikachu runs off with Ash following. Kiawe goes to join them but turns around and sees something that scares him. Ash and Rotom continue to follow Pikachu into the forest and find Rowlet on the floor. They run over to Rowlet but it becomes clear that Rowlet is sleeping. Rotom is confused as Rowlet doesn't usually sleep this much, but Pikachu draws their attention to Sophocles who has also fallen asleep by his sun-lounger. Ash runs over to him and manages to wake him up. Sophocles is unsure as to why he had fallen asleep and finds out that he is hungry now. At that moment, Rowlet's cookie comes out of the bushes which Rowlet flies over to. While the others are wondering what is going on, Morelull runs over, startling everyone.
Sometime later, Ash wakes up having fallen asleep and notices that Rowlet and Pikachu are looking like skin and bones. Rotom also doesn't remember going into sleep mode before noticing that its power has been drained. Sophocles wakes up, also looking like skin and bones saying that he is so hungry and they both collapse, feeling hungry. Ash and Sophocles along with Rotom, Rowlet and Pikachu return to the camp where everyone else apart from Lillie are all hungry. That night, everyone begins to feel better after having ferociously eaten their leftover curry (with the exception of Lillie). They then begin to review what had happened to them, but they only conclude that they had fallen asleep for no logical reason, and that when they woke up, they had been hungrier than they had ever been. Sophocles recalls seeing something before he had fallen asleep, and that it had looked like an umbrella. This makes Rotom realize what is happening and putting on his Laki wig, deduces that Lillie is the culprit, as he had noticed her open parasol and because she was the only one who had no appetite. However Mallow stops it, announcing that there was no way that Lillie could have done it.
As the group continue to discuss the events, Morelull appears from behind. Ash is excited to see a new Pokémon but Morelull releases its spores, which sends them all to sleep. Soon they all wake up, with everyone apart from Lillie feeling hungry again. As it is dark, Sophocles becomes scared and frantically searches for light. He accidentally touches a nearby Morelull which then illuminates its body. Rotom gives them data on Morelull, explaining that Morelull can send out spores, putting people and Pokémon to sleep before draining their energy. This leads Ash to guess that it was Morelull who had caused these events, as Lillie realizes she had never felt hungry because she had used her Max Repel to avoid touching wild Pokémon.
Morelull's illuminating light begins to flicker as it is begins to fall asleep which has Kiawe wonder whether its own spores had put itself to sleep. Ash, Pikachu and Rowlet move closer to Morelull, but Morelull sees them and backs away before releasing its spores. Rotom tells them not to look at the spores, but as Ash opens his eyes halfway, he sees Morelull draining Kiawe's energy. Morelull then goes over to the tents and hops on Lillie's bag, causing her Poké Doll to fall to the ground. Morelull tries to drain energy from the Doll but fails. Ash then introduces himself to Morelull, and Ash actually invites Morelull to drain his energy presuming that it is energy that the Morelull is after. Morelull then begins to take all the energy it wants from him, while Ash replenishes his energy by eating a plate of the curry. This process of Morelull draining Ash's energy before Ash replenishes it with the curry continues as the others look on with surprise. Soon all the curry is eaten up with both Ash and Morelull feeling stuffed. Ash holds his hand out to Morelull who takes it, and Sophocles notes that they have become friends. They then notice a glowing light in the distance, and realize that it is actually a group of more Morelull. Morelull leaves the group to go and join the other Morelull and everyone follows.
The Morelull are heading further into the forest as the group follows them. They end up at a clearing with a large tree where a large group of Morelull are standing, illuminating the tree. The Morelull start to glow, and they all evolve into Shiinotic at the same time. Rotom follows by providing data on Shiinotic, explaining that whilst they can drain energy, they can also share energy with those that they like. Meanwhile, flowers begin to bloom, and Ash realizes that the Morelull had been draining energy to help the tree. A Shiinotic comes over to them and they guess this it is the Morelull from before. Ash bends down to Shiinotic and says it was awesome that it had evolved. Shiinotic holds out its fingertips to Ash and Ash moves his fingertips to it, allowing them to touch. Shiinotic then releases more of its spores, sending everyone to sleep. Everyone wakes up the next morning, noting that they are not hungry anymore. Lana guesses that this is the Shiinotic's way of saying thanks for the energy they had given.