When the goddess Artemis goes missing, she is believed to have been kidnapped. And now it's up to Percy and his friends to find out what happened. Who is powerful enough to kidnap a goddess? They must find Artemis before the winter solstice, when her influence on the Olympian Council could swing an important vote on the war with the titans. Not only that, but first Percy will have to solve the mystery of a rare monster that Artemis was hunting when...

Jack and Annie, joined by Teddy and Kathleen (from earlier books), travel in the Magic Tree House to a land of snow where the Ice Wizard has captured Morgan and Merlin. The four friends must find the Ice Wizard's missing eye - or is it really his heart that is missing? 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....

When the goddess Artemis disappears while hunting a rare, ancient monster, a group of her followers joins Percy and his friends in an attempt to find and rescue her before the winter solstice, when her influence is needed to sway the Olympian Council regarding the war with the Titans.