The 1 bestselling chapter book series of all time celebrates 25 years with new covers and a new easytouse numbering system Its 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 minisubmarine 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 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 show more