I personally have not read this number in the series, but my kids love them all! My oldest read through all he had, now his 8 yr old brother is getting into them. I have read a few and think they are great for the imagination!
From back of book: Three...two...one...BLAST OFF! The magic tree house whisks Jack and Annie off to the moon-and the future. Their mission? To find the last "M" thing that will free Morgan from the spell. Can they do it before the air in their oxygen tanks run out? Will the mysteriuos moon man help them? And why is Peanut the mouse acting so strange?