You can find Lostelle in Three Island’s Berry Forest. Make your way to Three Island using your Tri-Pass on the Seagallop Ferry, go through the Bond Bridge and into the forest. Navigate your way through it and fight the Hypno that chased Lostelle. Bring her back to her father in Two Island to finish Bill’s quest.
Finding Lostelle
Lostelle is the daughter of the Bill’s friend in Two Island. When you first arrive in the Sevii Islands, Bill enlists your help in delivering a meteorite to his friend who is also a gem collector.
Ride the Seagallop Ferry to Two Island and look for the man inside the Game Corner building. He is distraught as he does not know where Lostelle is.
He mentions Lostelle might be in Three Island. Head on over there using your Tri-Pass on the ferry.
When you arrive, you see some biker goons harassing a poor woman. Continue on ahead and you will see a lot of them harassing other villagers.
Make quick work of them in battle. One of the grateful villagers will hand you a Full Restore, while the other will say he saw Lostelle run off to Bond Bridge up ahead.
Continue up north to the island to reach Bond Bridge. Make your way across it, fighting some unavoidable trainers along the way until you reach the Berry Forest.
Lostelle will be in the depths of Berry Forest. Navigate through it using the reference map below:
Talk to Lostelle when you find her. She got lost while picking berries because a “scary” Pokémon was chasing her.
You will then come face-to-face with a Hypno. Beat him in battle or catch him for yourself to save Lostelle.
You and Lostelle will then make it back to Two Island and her father will be thankful. You can then hand him the meteorite from Bill.
Go back to One Island and Bill and Celio will have finished their machine. You and Bill come back to Cinnabar Island after doing this side errand.
Once this preliminary quest is done, you can start doing the rest of the Sevii Islands quest which entails helping Celio gather the required gemstones for his long-distance network machine.
