A desert castle. An evil presence. A thirst for vengeance. Four teenagers are about to have a vacation they'll never forget. When Layla, her brother Adam, and their friends Zaid and Zahra, arrive at Dukhan Castle, they anticipate an exciting time exploring the mysteries of nature. They soon find themselves delving into mysteries of a different nature. A cloaked figure, spooky midnight screams, incense being burned in the eerie lookout tower, and startling secrets are just a few. The clues can only lead to one conclusion. Something sinister is simmering beneath the surface and it's just a matter of time before it breaks loose. A chance encounter with a gypsy woman begins a guessing game of intrigue, pitting the teenagers against a shadowy foe known as Al-Aqrab, the Scorpion. As danger draws closer to the castle, they must race against time to unmask the Scorpion and foil a demonic scheme of revenge. The Sign of the Scorpion is the thrilling second book in The Moon of Masarrah Series.