Heading to Snowbelle City, Ash inexplicably comes down with a fever. While Clemont and Bonnie head to the nearest town to get some medicine, Serena and the Pokémon stay behind to take care of Ash. However, soon after that, an unusual trainer and his Pikachu come by to challenge Ash to a battle. With the dream of defeating all trainer with a Pikachu, the trainer is insistent. With Ash unable to battle, it's up to Serena to pose as Ash and win the battle. Will she be able to live up to Ash's name?