"Where did the tree house come from? Before Jack and Annie can find out, the mysterious tree house whisks them to the prehistoric past. Now they have to figure out how to get home. Can they do it before dark ... or will they become a dinosaur's dinner?" -- Amazon.com

When Andy develops a severe toothache that prevents him from writing new jokes for their book, Terry uses their fantastical treehouse's money-making machine funds to purchase a Joke Writer 2000, with unexpected results.

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 favourite flavoured marshmallows into your mouth whenever it discerns you're hungry....

While Will has exciting adventures with aliens, mummies, and more, his little sister, Flora, captures them in pictures to hang in her treehouse, making them even better than Will imagined.

"Andy and Terry live in a 143-story treehouse. (It used to be a 130-story treehouse, but they built another thirteen stories.) Andy's been a bit stressed out lately, so Terry decides the perfect way to relax would be to head up to their new camping ground level for a much-needed vacation. But it turns out to be not quite as relaxing as planned. Terry forgets to pack the tent and the food, their attempt at fishing ends in disaster, the spooky campfire...

"Jack and Annie travel in the magic tree house to Galveston, Texas on September 8, 1900--the day of the worst natural disaster in US history"-- Provided by publisher.

"Andy and Terry live in a 169-story treehouse...It now has a kangaroo-riding range, a Whatever-Weather-You-Want dome, and a hall of fun-house mirrors--the perfect place to hide from the truancy officer who is trying to catch them and Jill and make them go to school! Unfortunately, the hall of fun-house mirrors is also the place where their evil troublemaking twins, Anti-Andy, Terrible-Terry, and Junkyard-Jill, live in a doppelganger mirror, and they...

In a land lost in mist, in a time before time, there is powerful Sword of Light. Now Merlin the magician needs that sword for the good of all Camelot. He turns again to Jack and Annie for help. With only a rhyme to lead them, Jack and Annie set out on a journey filled with fabulous creatures. But can they solve the ancient riddle before night falls?

"Join Jack and Annie as they as they meet one of the world's most famous illusionists - Harry Houdini!"-- Provided by publisher.

Jack and Annie are all shaken up! The magic tree house whisks them back to California in 1906. As soon as they arrive, the famous San Francisco earthquake hits the city. Can Jack and Annie find the final writing they need to help Morgan save Camelot? Or will San Francisco be destroyed first?