"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 live in a treehouse. But it's not just any old treehouse, it's the most amazing treehouse in the world! This treehouse has thirteen stories, a bowling alley, a see-through swimming pool, a secret underground laboratory, and a marshmallow machine that follows you around and automatically shoots marshmallows into your mouth whenever you are hungry. Life would be perfect for Andy and Terry if it wasn't for the fact that they have to write...