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?​

Gertrude Chandler Warner grew up in Putnam, Connecticut. She wrote The Boxcar Children because she had always dreamed about what it would be like to live in a caboose or a freight car―just as the Aldens do. When readers asked for more adventures, Warner wrote more books―a total of nineteen in all. After her death, other authors have continued to write stories about Henry, Jessie, Violet, and Benny Alden, and today the Boxcar Children series has more than one hundred books.