The Treehouse Books (14 book series)

The 13-Story Treehouse- Monkey Mayhem
The 13-Story Treehouse: Monkey Mayhem!
Andy and Terry live in a treehouse. But it's not just any old treehouse, it's the most amazing…
The 26-Story Treehouse
The 26-Story Treehouse: Pirate Problems! (Book 2)
Andy and Terry live in a 26-story treehouse. (It used to be 13 stories, but they've expanded.) It…
The 39-Story Treehouse
The 39-Story Treehouse (Book 3)
Andy and Terry are once again inviting readers to come hang out with them in their astonishing 39-…