After walking through the piles of volcanic ash in Route 113, you reach Fallarbor Town, where your neighbor seeks Professor Cozmo.
Explore the Town
Talk to the bug catcher in the Pokémon Center to get Honey.
Talk to the woman in front of the PC in the Pokémon Center. She is Lanette, who programmed the Pokémon Storage System. She asks you to visit her in Route 114.
Go south from the Pokémon Center and your neighbor will run up to you and take you to Professor Cozmo's house. Team Magma/Aqua have kidnapped the professor and taken him to Meteor Falls.
Use your Dowsing Machine and check inside the crater next to the professor's house to find a hidden Nugget.
Talk to the old man in the contest hall to get a Berry Blender for your base.
To the left of the Pokémon Center, there is the Move Maniac's house. If you give him a Heart Scale, the Move Maniac will teach a pokémon a move that it has forgotten or a move that it could have learned on leveling up but did not. There are hidden Heart Scales in certain places, and you might also find some by using Rock Smash on rocks, like the ones that blocked your path in Route 111.
Go west to reach Route 114.