This time, meet famous explorer Leif Erikson and help save a narwhal! When the magic tree house whisks Jack and Annie to Greenland, they're not sure what time they've landed in, but they immediately know what their mission is: save a narwhal! Then, they meet a young hunter named Leif Erikson, and they ask for his help. But Leif has other ideas.

The magic tree house carries Jack and Annie to New York City in 1938 on a mission to rescue the last unicorn.

The magic tree house transports Jack and Annie on a mission to the Ice Age where they encounter Cro-Magnons, cave bears, sabertooth tigers, and woolly mammoths.

The magic tree house takes Jack and Annie to Antarctica to search for the fourth secret of happiness for Merlin.

The magic treehouse takes Jack and Annie to a moon base in the future where they continue to search for the fourth thing they need to free their friend Morgan from the magician's spell.

"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"--

Who wouldn't want to live in a treehouse? Especially a 13-story treehouse that has a bowling alley, a see-through swimming pool, a tank full of sharks, a library full of comics, a secret underground laboratory, a games room, self-making beds, vines you can swing on, a vegetable vaporiser and a marshmallow machine that follows you around and automatically shoots your favorite flavored marshmallows into your mouth whenever it discerns you're hungry....

"Amelia Bedelia and her friends clean up a vacant lot and build a clubhouse--with surprising results! Includes a guide to idioms used in the book and features black-and-white art throughout"--