Vacation Under the Volcano is the thirteenth installment to the Magic Tree House series. The book is preceded by Polar Bears Past Bedtime and succeeded by Day of the Dragon King. It was written by Mary Pope Osborne and illustrated by Sal Murdocca.
Synopsis[]
The magic tree house takes Jack and Annie to ancient Pompeii just as Mt. Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.
Chapters[]
- A Secret Code
- The End Is Near
- Gladiators
- Scary Things
- Books? Books?
- The End Is Here
- The Sky Is Falling
- Nightmare at Noon
- Save Us
- A Simple Explanation
Plot[]
Jack and Annie, now Master Librarians, have received special library cards from the enchantress Morgan le Fay. Before their family vacation, Annie suggests they check the woods to see if the treehouse is visible again. Jack agrees, and Annie wonders if a disturbing nightmare about fires and ash in the sky might be a warning from Morgan. In the treehouse, Morgan greets them and gives them a mission to retrieve a lost book from ancient Rome. She hands them a book titled *Life in Roman Times*, telling them that it holds the key to helping in a future crisis, and gives them togas to wear.
The treehouse lands in an olive grove near Pompeii. Annie feels uneasy and wants to return home, but Jack insists they complete their task. They walk through the town, observing how similar Roman life is to their own. As they enter the city’s forum, they encounter a soothsayer who prophesies the end of the world. While searching for the library, the children pass public baths, a temple, and gladiators preparing for battle. They soon see the soothsayer again, and Annie speaks to her. The soothsayer warns of ominous signs: birds are gone, streams have dried up, the sea boils, and the earth shakes. These, she claims, signal the world’s end. Jack and Annie ask about the library, and she directs them to a man named Brutus’s house.

Hercules saving Jack and Annie.
At Brutus’s house, they find it empty, but inside they discover a room filled with scrolls— the library. After searching, they find the scroll they were sent to retrieve. Jack checks the book Morgan gave them to see if it mentions the scroll, but instead, he learns that Mount Vesuvius will erupt that very day. The sundial confirms they’re running out of time. As the ground trembles and the sky darkens, Jack and Annie rush back to the treehouse, protecting their heads from falling rocks. They reach a stream, but the bridge is destroyed, and they’re trapped in the ash-filled bed of the stream. Recalling Morgan’s advice, Annie takes the scroll and asks for help. A large man, dressed as a gladiator, appears and carries them across the stream. They finally reach the treehouse and return home safely.
Morgan is pleased with their success and thanks them for retrieving the scroll. She then tells them of their next mission in ancient China and gives them a book about Hercules. Jack and Annie speculate that the man who helped them across the stream was Hercules himself. They return just in time to head out on their family vacation.