The 39-Story Treehouse: Mean Machines & Mad Professors!

Andy and Terry have added thirteen new levels to their amazing treehouse! With a new trampoline, chocolate waterfall, active volcano, opera house, baby-dinosaur petting zoo, museum, boxing elephant, not-very-merry-go-round, X-ray room, disco dance floor, high-tech office, and the world’s scariest rollercoaster, the treehouse has gotten even more ridiculous!

As usual, Andy and Terry are too busy having absurd amounts of fun to realize that their next book is due tomorrow afternoon. Even though the boys have not written a scrap, Terry has a solution. He unveils his new top-secret invention: a Once-Upon-a-Time Machine that writes and draws the books for them. After the invention locks them out of the treehouse and threatens to write its own books, the duo must seek the aid of a mad professor, who is determined to destroy the universe, in order to save their treehouse.

Will the boys be able to save the universe and the treehouse all while finishing their book?

The Treehouse Series is a fantastic series for young readers who are reluctant to read. Griffiths and Denton create a silly, funny, and ridiculous story that will leave readers rolling on the floor laughing. In order to finish their book, Terry invents a machine that will write the book for them. After the machine locks the boys out of the treehouse, Andy and Terry go through a range of slapstick scenarios in order to save their treehouse and book series. In the end, the boys realize they should have written their book and not have depended on the machine to do it for them. This teaches readers the importance of doing their own work.

Unlike other books in the series, Griffiths and Denton do not depend on bathroom humor or inappropriate behavior as a crutch for their jokes, but instead, use wordplay and a bit of slapstick comedy to entertain their readers. The funny black-and-white drawings contribute to a positive reading experience and will help younger readers transfer their reading skills from picture books into full-fledged novels.

Unlike other series, readers can enjoy each of these books by themselves and the series does not have to be read in order. In the end, this fun, easy-to-read book will teach readers the importance of doing your own work and encourage reluctant readers to finally read. The story’s fast pace and silly situations will keep readers turning the pages until the very end.

Sexual Content

  • None


  • In the treehouse’s baby-dinosaur petting zoo, one of the velociraptors bites one of Andy’s fingers off. It is illustrated, but not gory or violent.
  • The Once-Upon-A-Time Machine slaps the boys “away whenever we get too close to the treehouse.”
  • The Trunkinator, a giant boxing elephant, “stomps into the room and punches [Professor Stupido] in the nose.”

Drugs and Alcohol

  • None


  • After Terry’s jet-propelled swivel chair malfunctions, he calls it “stupid.”
  • When the Once-Upon-A-Time machine refuses to let Terry and Andy in, Terry yells, “You’re just a dumb machine that I invented! Open the treehouse door! NOW!”
  • Professor Stupido, the world-famous un-inventor, is a main character in this book. He calls penguins “stupid, flightless things.”


  • None

Spiritual Content

  • None

by Matthew Perkey

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