Ash, Serena, Clemont, and Bonnie finally arrive in Coumarine City. While there, Bonnie sees an ice cream stand and asks for an ice cream cone. After she remarks about it being in the shape of a Vanillite, the man at the shop tells the group about a Vanillite that is being looked after by Nurse Joy at the Pokémon Center. The group decides to go see it, and so, not knowing about the monorail, they begin a long trek up the hill that leads to the other side of Coumarine City. Clemont, getting worn out much more quickly than the other three, shows off an invention that allows him to move up the hill with ease, but it goes awry and sends him crashing through a gate and into a field that is a pasture for Grass-type Pokémon. He is then attacked by a group of angry Victreebel, but is saved by a man riding a Gogoat. The man, after accepting their explanation for being in a reserved area, allows them to take a shortcut through his ranch to get to the Pokémon Center.
At the Pokémon Center, Nurse Joy introduces the group to the Vanillite under her care. While Vanillite is shy at first, it quickly begins to trust them and plays happily with Pikachu and Dedenne. Nurse Joy accepts everyone's offer to help her and they all go to another room to prepare food for Vanillite. However, Team Rocket disguises themselves as Nurse Joys and runs off with Vanillite, leading everybody to chase after them and pursue them up the same hill they went on to traverse the fields between the two halves of Coumarine City. While in Team Rocket's clutches, Vanillite manages to cry loud enough for its family, a Vanillish and Vanilluxe, to hear it. In response, Vanillish and Vanilluxe use Blizzard, summoning a raging snowstorm that covers Coumarine City in snow.
Ash and his friends finally catch up to the three false Nurse Joys, who reveal themselves as Team Rocket and recite a variation of their motto. As the blizzard worsens, Vanillish and Vanilluxe arrive and attack both Team Rocket and Ash and company. They freeze Team Rocket in a block of ice and try to do the same to the others, but Ash runs forward and tries to stop them. Before he can be frozen as well, the man from before—named Ramos—arrives and Gogoat uses Vine Whip to pull Ash out of harm's way. Lecturing Ash on the difference between attacking head-on and taking "the side road," he has his Jumpluff use Sunny Day and then tells his numerous Sunflora to unite and use Solar Beam to melt all of the snow, which appears to calm down Vanillish and Vanilluxe.
However, a newly thawed Team Rocket moves over to their next plan and produces a giant Meowth-shaped robot to continue with their plot to steal Vanillite and the others. Inserting the three Pokémon into the machine's "cold collectors", they begin forcibly taking the cold energy from the three Ice-type Pokémon and using it to attack Ash, Serena, Clemont, Bonnie, and Ramos. When they explain the workings of their machine, Clemont is impressed with their scientific prowess, but Bonnie scolds him and they continue to battle. Clemont's Luxio, Ash's Pikachu, and Serena's Fennekin all start to attack the robot, but to no avail, as the frigid air from Vanillite, Vanillish, and Vanilluxe stops their attacks. In response, Ramos has his Gogoat use Grass Knot and Leech Seed on the robot, effectively immobilizing it. With Frogadier's Cut and Pikachu's Iron Tail, the three Pokémon are freed and Team Rocket is sent blasting off with a barrage of attacks from Frogadier, Pikachu, Fennekin, and Luxio.
Back at the Pokémon Center, the group, Ramos, and Nurse Joy all say goodbye to Vanillite, Vanillish, and Vanilluxe. Ash and his friends finally introduce themselves to Ramos, and they learn his name—a name which Clemont recognizes, but cannot immediately remember. Ramos tells Ash how he must remember to always take the side road in life sometimes. Just as Ramos is leaving, Clemont remembers that Ramos is the Coumarine Gym Leader and Ramos tells Ash that he will be waiting for his Gym challenge.