Set in the Art Institute of Chicago’s Thorne Rooms, 68 miniature rooms of different times and locations, sixth-graders Jack and Ruthie have located a magic key which enables them to shrink and visit the rooms. However, they discover that some of the artifacts are disappearing and they realize that they are being stolen. The pair set themselves to find the thief, restore the treasures and help some new friends from the past that they meet in the rooms. This book is a sequel to The Sixty-Eight Rooms but stands well on its own as a magical mystery and adventure. Reviewed by BPL volunteer EE.