"Beware of Wikings!" 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 lookinf 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...

Mary Pope Osborne is the author of all the Magic Tree House books, as well as American Tall Tales and New York’s Bravest for Knopf. The author lives in Goshen, CT.Sal Murdocca has been illustrating and writing books for children for many years. He has illustrated every book in the Magic Tree House fiction series and the Magic Tree House Research Guide nonfiction companions. Sal and his wife Nancy are avid runners and have toured Europe on bicycles. He lives in Rockland County, NY.