I entered the Sootopolis City Gym after I stopped the Groudon that was causing droughts all over Hoenn. I started walking on the icy floor, but I made a mistake and I fell through to the bottom room, and I had to battle some trainers there. I headed out to the Pokemon Center to heal my Pokemon after that, and once I was back at the Gym I decided that I may as well battle against the other Gym trainers to earn some experience points. I kept battling until all the Gym trainers were beaten, but my Pokemon still weren't exactly strong enough to battle against Wallace's team. I healed my Pokemon again and purchased some items at the local Poke Mart, then I went underwater and I battled some of the wild Chinchou and Clamperl that appeared in the seaweed. That wasn't enough though, so I went back to the Cave of Origin and I trained there. I then returned to the Gym and saved.