Sapphire is looking for the entrance to the underground that she fell in earlier. Wattson and the Trick Master are curious to know where she fell since they have been looking for it for a while. Sapphire slams the exact area on the ground with her fist and the entrance opens up. The three take a peek from above. Wattson asks her what the location in the underground is called. Sapphire answers, but is interrupted by a group of kids that want to battle Wattson. Wattson accepts all of their challenges and sends out Electrike and two of his Magnemite. Wattson's Electric-types easily defeat the six challengers. One of them mentions that Wattson is a Gym Leader which shocks Sapphire.
Sapphire gets angry and asks him if Wattson is a Gym Leader, which Wattson confirms with a laugh. Despite the challengers losing, Wattson rewards each of them a Gym Badge since the attacks their Pokémon performed were very powerful. Sapphire then questions him about giving out Gym Badges to challengers that didn't defeat him. Wattson was then saying that the Badges are proof of the Gym battle. Sapphire wonders if that was a Gym battle as the kids walk away. Wattson then continues his statement by saying that his battle motto is "Be cheerful, no matter when or where", and that any battle performed by him is a Gym battle. He would give out Gym Badges to anyone that has impressed Wattson during the Gym battle as stated by the Pokémon Association.
Since Sapphire showed him to the entrance to the underground earlier, he rewards her with the Dynamo Badge. Sapphire rejects the offer by slapping it away, sending the Badge flying. She explains to him that she would only earn Badges if she defeats the Gym Leader, not the Gym Leader giving them away for free. Wattson accepts her personality and the Trick Master wonders where the Badge that flew out of Wattson's hand went. The Badge is revealed to have landed on a Donphan, which ends up angering it. Donphan chases the three and they fall into the underground. Sapphire wakes up Donphan and the Trick Master. After they wake up, they fight each other. Sapphire tells the Trick Master to cut it out.
The Trick Master turns the lights on and mentions that he found New Mauville. He turns around to see Wattson, but Wattson isn't there. The Trick Master tells Sapphire the story behind New Mauville. The underground city was created by their ancestors since Mauville was known for the overcrowding of children. With New Mauville built, the problem of not having enough land disappeared. It turns out that both Wattson and the Trick Master love children. After Sapphire listens to his story, she asks the Trick Master for his help in finding the mystery of the underground city in exchange for a proper Gym battle. The Trick Master accepts. Sapphire calls out his name to see if he could hear her. Wattson did hear her and tells her to come over here.
Sapphire dashes over to where she heard Wattson, but instead finds his Electrike and Magnemite. The Magnemite have fallen to the ground since their electrical supply was drained by the power generator. With Electrike alright, Sapphire tells him to lead the way to where Wattson is. Sapphire picks up the Magnemite and she along with the Trick Master follow Electrike. Electrike takes them to Wattson, who is stuck to a power generator that is out of control and sucked the electricity out of Voltorb and Electrode. However, the generator noticed them coming and attacks them with the electricity that it had drained from the Electric-type Pokémon.