Mystery of the Hidden Elves — Gertrude Chandler Warner

The Aldens have joined Dr. Iris Perez as she investigates legendary creatures around the world. In this adventure, the children travel to Iceland to look into stories of mischievous elves causing trouble. The legends of huldufolk, or hidden people, go back a long way in the country, but are elves really the cause of the problems, or is there a more natural explanation for the strange events on the island?​