Magical chills and thrills! Jack and Annie are on a mission to learn the final secret of happiness! This time, the magic tree house whisks them away to the super-cold continent of Antarctica, the land of ice and snow and penguins. Where they're supposed to find the Cave of the Ancient Crown. But when they meet a group of scientist and reporters, Jack and Annie are surprised to discover that they are in contemporary times! How will they find an ancient crown if they're with these people?