The magic treehouse takes Jack and Annie to a moon base in the future where they continue to search for the fourth thing they need to free their friend Morgan from the magician's spell.
"When the magic tree house whisks Jack and Annie back in time, they land in the tallest tree in Yosemite, California where they join nature conservationist, John Muir, and US President Teddy Roosevelt on a historic trip through the woods"--
Their magic tree house takes Jack and Annie back to a monastery in medieval Ireland, where they try to retrieve a lost book while being menaced by Viking raiders.
Their magic tree house takes Jack and Annie back to retrieve a lost story in ancient Greece, where they witness the original Olympic games and are surprised to find what girls of the time were not allowed to do.