How do you get the people of Wormwood Creek in Dragon Quest IX to trust you?

you must give Serena the serene necklace, and then have her unlock the bowhole dungeon for you. get to the bottom of the bowhole, then fight gadorongo and obtain the wrymlight bow. then, go back to wormwood canyon and a scene will unfold.

now give the ghost girl her neckalce, have her unlock the dungeon, then fight the monster and get the weapon. then, continue on to the next town