"The magic tree house whisks Jack and Annie away to South America, where they must climb Machu Picchu to save a baby llama" -- Provided by publisher.

We are warriors! Jack and Annie have met knights, pirates, ninjas, and Vikings, but they have never met the most fearsome warriors of all: Roman soldiers. When the magic tree house whisks them back to the early 100s AD, Jack and Annie find themselves in a Roman camp. Their mission: Be like a warrior. That is easier said than done! The Roman soldiers are much scarier in person--and suspicious of strangers. Then a mysterious man riding a black horse...