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.

The magic tree house carries Jack and Annie to New York City in 1938 on a mission to rescue the last unicorn. In this exciting new Merlin Mission, Jack and Annie go back in time to New York City, during one of the darkest periods in the city's history--the Great Depression. Even worse, the city is in the grip of a terrible snowstorm. To stop the blizzard, Jack and Annie must save the unicorn made famous in the Cloister's medieval tapestries. But will...

While on a mission to prove to Merlin that they can use magic wisely, Jack and Annie travel to seventeenth-century Venice, Italy, to save the city from disaster.