After you've defeated Mayleene your rival will be waiting for you. Lucus/Dawn will tell you that Team Galatic has his (Lucas)/her (Dawn) PokeDex. Go after your friend to the warehouse and help him/her out. After doing so Looker will have a little chat with the two of you. Follow Looker in and you will see a PokeBall. That PokeBall contains HM 02 FLY.
Chat with our AI personalities
at the city of the Pokemon league
it's no
no
fly
there is none buckaroo. tough nuts.