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 starts with thirteen stories, a bowling alley, a see-through swimming pool, and a secret underground laboratory. And it keeps getting bigger! Soon the treehouse has twenty-six stories, then thirty-nine as Andy and Terry keep adding more levels and rooms, including a skate ramp, anti-gravity chamber, an active volcano, a chocolate waterfall and more!