Season of the Sandstorms

This installment in the Magic Tree House Merlin Missions series follows siblings Jack and Annie, who travel through time using a magic tree house that belongs to Morgan le Fay, a magical librarian from the legendary realm of Camelot. The wizard Merlin has been sending them on missions to prove they can use magic wisely in real historical settings. Two young sorcerers, Teddy and Kathleen, have given them a handmade book of ten magic rhymes, each usable only once. Jack and Annie have already used two rhymes on a previous mission in Venice, leaving eight for three remaining missions.

One afternoon, Annie rushes into Jack's room to tell him the magic tree house has reappeared in the Frog Creek woods. They climb up and find a gold-covered research book titled The Golden Age of Baghdad along with a letter in Merlin's handwriting. The letter instructs them to journey to ancient Baghdad and help the caliph, the ruler of the Arab empire, spread wisdom to the world. It also contains cryptic rhyming instructions: ride a "ship of the desert" on a cold starry night, find a horse on a dome behind a third wall, greet friends beneath singing birds in a "Room of the Tree," and return before the moon rises. Jack worries, but Annie urges him to wish them there, and the tree house spins.

They arrive wearing long robes, head cloths, and pointy shoes at a small desert oasis surrounded by miles of scorching sand, with no city in sight. Jack reads that from 762 AD to 1258 AD, a caliph governed the Arab empire from Baghdad, an important center for learning and trade. With no way to reach the city, they use the rhyme "Make Helpers Appear out of Nowhere." A sandstorm blows through, and when it subsides, bells announce a caravan of camel riders.

The caravan leader, a stern merchant named Mamoon, explains the sandstorm diverted his group to the oasis. Annie tells him she and Jack were separated from their family, and Mamoon expresses concern about desert bandits. To earn his trust, Jack and Annie spend the afternoon gathering dates from palm trees in the heat. Mamoon invites them to share tea and dates with his men.

When Annie mentions they need to reach Baghdad to meet the caliph, the riders laugh, saying the caliph does not meet with children. Mamoon offers to let them travel with the caravan, calling camels "ships of the desert," a phrase Annie recognizes from Merlin's instructions. Jack struggles with his camel, whom Annie names Beauty. The animal chews his head cloth, spits at him, and tugs at his bag. Mamoon teaches Jack to respect camels by describing their remarkable abilities, and Jack remembers Merlin's instruction to be humble. The caravan sets off under a star-filled sky, with Mamoon navigating by the stars, fulfilling the first of Merlin's clues.

A fierce shout interrupts the ride as dark figures on horseback charge toward the caravan. Mamoon thrusts a flat wooden box into Jack's hands, ordering him and Annie to protect it with their lives. Beauty bolts, and the two camels gallop into the dunes. When hoofbeats approach, Jack and Annie frantically bury the box in the sand. The rider turns out to be Mamoon, who reports that the bandits have been driven off. Annie digs up the box and returns it. Mamoon calls it a priceless treasure brought from Greece but does not reveal its contents.

Heading east toward the morning sun, a massive sandstorm descends. The wind rips the box away, and Jack chases it through blinding sand. When the storm passes, Mamoon is gone, but their camels return on their own. Jack pries open the cracked lid and finds not gold or jewels but a book: The Writings of Aristotle. He reads that Aristotle was an ancient Greek philosopher whose works were introduced to the Western world by the Arabs. Annie connects this to their mission: they must deliver Aristotle's book to the caliph so he can share its wisdom.

The desert gives way to farmland and roads crowded with travelers. Jack and Annie cross a river, pass through a huge outdoor market called a bazaar, and ride through three concentric walls of increasing height. Beyond the third wall stands a palace with a glittering green dome topped by a horse statue, matching Merlin's clue. In the courtyard, boys laugh when Annie says she has come to see the caliph. She brags about saving a treasure from bandits, and Jack scolds her for not being humble.

Back at the stable, they discover Beauty has chewed Aristotle's book to shreds. Annie blames herself for bragging, and both are devastated. Then Annie remembers the rhyme "Mend What Cannot Be Mended." They gather the torn pieces, read the rhyme, and the fragments swirl into a tornado of light that restores the book completely.

A veiled servant girl appears and silently leads them into the palace. At a tall carved door, a boy servant stands guard. The girl whispers instructions: bow before the chair, do not look up, and do not speak until spoken to. Inside, they find the Room of the Tree, a chamber dominated by a giant tree with silver leaves and mechanical golden birds singing from its branches. Jack and Annie kneel before a jeweled black chair. A deep voice asks why they have come. Jack presents the book as a gift of wisdom for the caliph. The man offers perfumes, rubies, and gold in payment, but they refuse every reward. Annie suggests the caliph use his wealth to buy more books. The man's voice turns gentle and familiar. He tells them to look up. It is Mamoon.

He reveals that he is Caliph Abdullah al-Mamoon. He had long wanted a book of Aristotle's wisdom found in Damascus and disguised himself as a merchant to retrieve it, with his fellow travelers unaware of his identity. He praises Jack and Annie for their humility and respect for books, then takes them in a royal carriage to the House of Wisdom, a large brick building containing a laboratory, an observatory, and a library. In the sunlit library, the caliph introduces the mathematician al-Khwarizmi, who perfected the Arabic numerals, and the scientist al-Kindi, who believes wisdom must be shared for the world to grow wise. The caliph shows them a book of Tales from the Arabian Nights and reflects on the power of books to carry stories between lands. He promises to have Aristotle's book copied and shared, then bids them farewell.

Jack and Annie recall Merlin's final instruction: return before the moon rises. The sky is already pink with sunset, and the tree house is a full day's ride away. They choose the rhyme "Fly Through the Air," and the carpet beneath their feet lifts off, soars out the library window, and carries them over Baghdad, the desert, and the dunes back to the oasis. They climb into the tree house just as a crescent moon appears, confirming they have completed all of Merlin's instructions. Jack wishes them home, and the tree house spins them back to Frog Creek.

Walking home through the spring woods, Annie notes they passed Merlin's test by helping spread wisdom. She speculates that the veiled servant girl and the boy at the palace, whose faces were never visible, may have been Teddy and Kathleen in disguise. Jack considers the possibility. With two missions and five rhymes remaining, they hurry home.