Flannery's Gym has a unique floor puzzle involving hidden holes. The gym is filled with steam, obscuring your vision. You need to navigate through a series of rooms, stepping on specific tiles to fall through holes and land in the correct spot on the floor below. There are several trainers (Kindlers and Battle Girls) scattered throughout, using Fire-type Pokémon like Slugma and Numel. The puzzle can be a bit tricky, but if you fall into the wrong hole, you'll simply be sent back to the previous floor. The key is to find the path that leads you to Flannery's platform. Battling all trainers is recommended for experience.
