"Jack and Annie use the magic tree house to travel back in time to 1947 Brooklyn, New York, where they pretend to be batboys at Jackie Robinson's first game with the Brooklyn Dodgers against the Boston Braves"--

The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system!
The magic tree house has returned and it’s taking Jack and Annie back in time to Alaska, 1925. There they meet Balto, a jet-black Siberian husky destined to save victims of the diphtheria epidemic. But the trail isn’t easy, and Balto is going to need Jack and Annie’s help!
Formerly numbered as Magic...

Their magic tree house takes Jack and Annie deep into the sea, where they meet up with dolphins, sharks, and octopi as they search for the answer to an ancient riddle.

Their magic tree house takes Jack and Annie to the Arctic, where a polar bear leads them onto very thin ice.

Their magic tree house takes Annie and Jack to Pompeii just as Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.

Eight-year-old Jack and his younger sister Annie use the magic treehouse to travel back to the Middle Ages, where they explore a castle and are helped by a mysterious knight.

"Nine long months after being shut out of the pillow fort network for good, Maggie and Abby finally have a whole new mission to focus on--and this one starts with a return to the infamous Camp Cantaloupe. Abby needs this trip after a year of big, BIG changes back at home. But Abby knows that Maggie will never relax until they've solved the lingering puzzle left over from last summer: the mystery of the trap door in Camp Cantaloupe's historic Shipwreck...