Useless treasure

Exploration Stage: Old Cottage
From: Rayden Storke
Description: There was a story in that book, I believe, about a dragon and a princess. As a child, I dreamed of defeating the dragon and rescuing the princess. Now I have to save Keira, who is trapped by Goodman. If there is a dragon with an artifact in it, it might help me. Let's find the dragon.
Completed: You found the coin case of the dragon! There must be some kind of treasure inside. It may be exactly the artifact you are looking for! Unfortunately, the only thing inside this dragon is a nondescript coin. Thanks to this, it seems to have angered Goodman. Hopefully no harm will come to Keira...