Pokémon FireRed and LeafGreen/Three Island

'''The last of the Sevii Islands, Three Island is full of bikers harrassing the local residents. Head up north to enter the city.'''

Three Island
Three Island has been overridden with bikers who want to take island for themselves. When you first arrive, it's not much; only a Pokemon Center and Lostelle's house are available. Be sure and talk with the yellow haired guy by the P.C. - he'll mention that they're finally working, which lets you use them.

Where's Lostelle?
When you visit the house, it's empty. Perhaps the sudden appearance of the bikers is the problem.

Biker Gang
Head slightly north to see some bikers blocking the path. As usual, you'll have to save the day. Walk up to challenge the first bikers (or decline if you want to wait). You'll be challenged to four straight battles with no chance to heal in between, so be sure your Pokemon are rested.

After defeating Paxton, the rest of the bikers will run off. Talk to the two residents that you saved and one of them will give you a full restore, while the other will mention that Lostelle has gone towards Bond Bridge.

The rest of Three Island has also opened, revealing a Pokemart along with several houses. Talk with the girl in the house with the purple roof who says Lostelle was headed towards Berry Forest.

Use cut for a Zinc on the east side and a hidden PP Up on the west side. When you're finished with the town, head out to Bond Bridge in search of Lostelle.