The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system ``Beware of Vikings `` warns Morgan. Then Jack and Annie are whisked back to ancient Ireland. They land on a cliff on a misty island. How will they find the story they are looking for? It will take a Viking invasion, the help of a jolly monk, and a lot of courage for Jack and Annie to succeed in Viking Ships at Sunrise. Did you know that theres a Magic Tree House book for every kid? Magic Tree House: Adventures with Jack and Annie, perfect for readers who are just beginning chapter books Merlin Missions: More challenging adventures for the experienced reader Super Edition: A longer and more dangerous adventure Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures Have more fun with Jack and Annie at MagicTreeHouse.com