"When Jack and Annie receive an invitation to spend Christmas Eve in Camelot--a magical place that exists only in myth and fantasy--they know they are in for their biggest adventure yet. What they don't know is that the invitation will send them on a quest to save Camelot. Can they succeed even though Camelot's greatest knights have failed?"--Amazon.com.

Jack and Annie are joined by Teddy and Kathleen as they travel to the snowy Land-Behind-the-Clouds, where they search for the eye of the Ice Wizard and attempt to help Merlin and Morgan.

Jack and Annie have four time travel adventures involving Alexander the Great, Harry Houdini, Florence Nightingale, and Pele.

"'Please come to Camelot.' When they read this note, Jack and Annie know they must travel to Camelot and the castle of King Arthur. The magic tree house whisks them through time and space, where they find that the castle itself has been attacked and King Arthur himself has been gravely wounded. To save the kingdom -- and the king -- Jack and Annie must solve a riddle, trick a band of robbers, and journey to the worlds of myth to find a missing dragon....