Morgan le Fay will make Jack and Annie masters of the tree house if only they can solve four riddles. "Dolphins at Daybreak" begins the third set of four books in the magical series, as Jack and Annie embark upon solving riddle number three in a whole new world under the ocean!

Morgan le Fay will make Jack and Annie masters of the tree house if only they can solve four riddles. "Dolphins at Daybreak" begins the third set of four books in the magical series, as Jack and Annie embark upon solving riddle number three in a whole new world under the ocean!

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system!

It's sink or swim for Jack and Annie when the Magic Tree House whisks them off to the middle of the ocean. Luckily, they find a mini-submarine on a coral reef. Unluckily, they are about to meet a giant octopus and one very hungry shark. Will the dolphins save the day? Or are Jack and Annie doomed to be dinner? Did you know that there's 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