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....

Andy and Terry's 13-storey treehouse is the most amazing treehouse in the world! It's got a bowling alley, a see-through swimming pool, a tank full of man-eating sharks, a giant catapult, a secret underground laboratory and a marshmallow machine that follows you around and shoots marshmallows into your mouth whenever you're hungry. Well, what are you waiting for? Come on up!

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.

When their over-the-top ideas expand their amazing treehouse to include a giant submarine sandwich shop and a human pinball machine, Andy and Terry find themselves babysitting Mr. Big Nose's three troublesome grandkids.

The magic treehouse whisks Jack and Annie back to the days of deserted islands, secret maps, hidden gold, and nasty pirates.

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.

Andy and Terry recount the story of how they first met, an adventure marked by emergency shark operations, giant storms, and wooden pirate heads.

"Andy and Terry are once again inviting readers to come hang out with them in their astonishing 39-story treehouse (it used to be 13 stories, then 26 stories, but they keep expanding). And this year they will have even more time to jump on the world's highest trampoline, toast marshmallows in an active volcano, swim in the chocolate waterfall, pet baby dinosaurs, and go head-to-trunk with the Trunkinator, since Terry has created the greatest invention...

Andy and Terry must get past their differences to save their story ideas from a herd of spy cows.

Andy and Terry live in a 130-story treehouse. It used to be a 117-story treehouse, but they added another 13 stories. It has a soap bubble blaster, a time-wasting level, a 13-story igloo, the GRABINATOR (it can grab anything from anywhere at any time). It is a toilet paper factory, and an extraterrestrial observation center for observing aliens. As it turns out, though, it's Andy, Terry, and Jill who are being observed and then abducted by a giant...