Appendix:User142 Ruby Sapphire walkthrough/Petalburg City
From Bulbapedia, the community-driven Pokémon encyclopedia.
Go to the gym, and talk to the person there. This person is your father. While you talk to him, someone else comes in and asks for a Pokémon. This person is Wally, the kid from next door. Your father lends him a Zigzagoon, and sends you with Wally. Wally catches a Ralts, and then returns with you to the gym.
