In the Hall of the Mountain King by Megan Endicott

In the Hall of the Mountain King by Megan Endicott

Peer Gynt, a naughty little boy who disobeys his mother to stay out searching for treasure, discovers a magnificent cave that leads him deep into the heart of another world.

Peer Gynt is a naughty little boy who often steals, plays mean tricks, and never helps his mother. More than anything else, Peer enjoys searching for treasures near his cottage in the mountains of Norway. Every day he leaves his cottage to go treasure hunting, and every day his mother asks him to be home before dark. However, one night-a particularly magical night-Peer decides to ignore his mother's request and continues searching for treasure long after the sun has set. He discovers a marvelous cave, the likes of which he's never seen before. Certain that there must be magnificent treasures within, Peer ventures deep inside the cave. His expedition leads him straight to the center of the mountain, into the hall of the Mountain King.

As mischievous Peer Gynt soon learns, the Mountain Kingdom is a land of the extraordinary. He finds himself face-to-face with beings of myth and magic and a greater danger than he's ever encountered in his life. Will he survive to tell his mother where he's been?