On the way to Eterna City, our heroes visit a Pokémon Center where they meet young Paige and her big sister Marnie, the daughters of the local Nurse Joy! Ash and his pals get their first good look at Drifloon—Marnie has three, which she uses to help her deliver lunch to her father while Paige takes the gang to meet Pokémon in the surrounding forest. Paige also reveals she and Marnie have a secret friend, none other than the legendary Suicune!
Marnie's father and his Ampharos are working at the Valley Windworks Power Plant. Team Rocket tries to steal Ampharos, only to be shocked by Ampharos's Thunder. But the resulting explosion damages the Windworks, and when the lights go out at the Pokémon Center, Nurse Joy sets out for the Windworks to see what's wrong. Paige wants to take her Drifloon and follow; Pikachu tries to stop her, but a gust sweeps all three of them away!
Ash and his friends race to the Windworks to try and intercept them, except a looming storm blows Paige and Pikachu way off course. Ash finds them with the help of Marnie's Drifloon, but they're stuck up among the rocks and there's no way the others can reach them on foot any time soon. Marnie is determined to save her sister no matter what, so she asks Suicune to appear and help her. Suicune responds and quickly takes her to Ash and Paige, then brings everyone back to safety. With Nurse Joy's family reunited and the Windworks Power Plant fixed, our heroes can call it a day!
Ash and his friends finally arrive at Valley Windworks. They find the Pokémon Center but are confused because it looks old and unappreciated but they go inside anyway, and nobody appears to be there at first sight. When they open the door, multiple Gastly come out of the center. They come into a kitchen area and see some dinner on the table. Ash goes over to see what is in it but a young girl shouts at them as she thinks that Ash is a thief trying to steal her food. She whacks her broomstick on Ash's head. After the commotion, they meet Nurse Joy, as well as two younger Joys. Nurse Joy and her older daughter were out shopping. Brock realizes that she's married and becomes upset. Ash and friends are invited to eat after the commotion and Nurse Joy's daughters Marnie and Paige introduce themselves to the gang and explain that when they grow up they want to be Nurse Joys. They explain that they want to work full-time at the Pokémon Center with their mother. Ash and the gang offer to help them all out whilst they stay at the center. Brock offers to be Nurse Joy's Pokémon assistant. Dawn and Marnie are doing the laundry whilst Ash and Paige are cleaning the center. Paige realizes her husband has forgotten his lunch and Marnie says that their Drifloon can help solve the problem. Marnie uses the Drifloon to Fly to the generator where her father works in order to bring his lunch to him. Paige is upset that she doesn't get to go along as well, so Nurse Joy has Paige give the forest Pokémon treats to appease her. She calls its a special job that only Paige can do. Paige asks Ash to come along with her and he accepts.
While they are walking through the forest handing out the treats, Ash tells Paige that she has a lot of friends but Paige tells Ash that she has another Pokémon friend, but Marnie told Paige not to say the name of it to others. Paige realizes that she won't get in trouble if she shows Ash her friend, so she takes Ash to go see them. Paige leads Ash over to a misty lake and calls out for her friend, but gets no response. Ash asks what type of Pokémon it is, and she informs him that it is a Suicune. Ash is surprised, as it is a legendary Pokémon. Paige insists that it is true.
Meanwhile, Marnie arrives at the power plant. Marnie's father is seen fixing something there with the assistance of his Ampharos. At the same time, Team Rocket is shown looking through the bushes at the two of them. Meowth convinces the other two to try and steal the Ampharos. Marnie's father is warning her that a storm is coming when suddenly Team Rocket snatches Ampharos in a net and they recite their motto. Marnie's father orders Ampharos to use Thunder, which sends Team Rocket blasting off. However, the explosion from the blast damaged the power lines.
Back at the Pokémon Center, Nurse Joy is talking to Paige when suddenly the power goes out. Nurse Joy suspects that something happened at the power plant, and decides to go check it out. She tells Paige that she can't come, and Paige runs outside to go to the power plant. Ash tells Nurse Joy that Pikachu will stop Paige and Nurse Joy thanks them and rides to the plant on her bike. They notice that the wind is getting fierce. Pikachu attempts to hold her down as she tries to fly off with a Drifloon. Ash, Dawn, and Brock tell Paige about the dangers of going to the plant in this weather. But before they could react, the winds in the storm became so strong that both Pikachu and Paige are blown away.
At the power plant, the Joys have fixed the power plant. Ash and friends ask them if they saw Paige, but they hadn't. Ash explains that Paige tried to come here by Drifloon and Joy's husband tries to track the last wind gust. He goes on to say that all the winds are headed in the direction of the mountain and that there will be more of them. Ash grabs Marnie's Drifloon and flies off in search of her. Meanwhile, using Paige's and Marnie's father's car, the rest of the gang goes out looking for Paige and Ash. Pikachu and Ash can be seen in the mountain range with Drifloon but it starts to rain heavily and Paige is scared by the thunder. Unfortunately, a boulder is blocking the road and they can no longer continue. Ampharos tries to use Thunder Punch on the rock but it barely moves. Marnie rushes home and tells the others to go on ahead. She did this to get help from their friend, Suicune. She travels through the forest but the lightning felled two trees and Marnie falls to her knees. She regains confidence as Paige needs help and runs to find Suicune. Marnie asks Suicune to carry her on the North Wind to help find where Paige is. Marnie gives up as Suicune doesn't answer her call and says that she just wants someone to help. She realizes that Paige is her sister and it's her job to rescue her and no one else. Just before she leaves, Suicune appears and takes her to the mountains.
Meanwhile, Ash has found Paige. They shelter in a small cave and he reassures Paige that the rest of them are looking for them and they will return home safely. The two of them decide to try to get home after the storm ends. As Ash and Paige cross a log as there is no other choice (used as a bridge) they fall. Marnie appears with Suicune and saves the two. In the end, the family is reunited. Dawn and Brock want to know about Suicune, but it has already left. As they leave, Ash and Marnie exchange a knowing glance while Suicune watches them from the peak of a cliff.
Exhausted and disappointed due to their previous loss, the Team Rocket trio spots a Suicune near the cliff and makes a vain attempt to catch it. But in the blink of an eye, the legendary Pokémon blasts them off with its Aurora Beam.