It tells the story of John and Philippa Gaunt and their adventures when they find that they are djinn, or mystical genies.

[1] The book was sold as part of a trilogy to Scholastic Publishing for a then record 1 million GBP.

Their uncle Nimrod appears to them in a dream and tells them about their magical powers as djinn.

Nimrod, John, and Philippa encounter various adventures while trying to discover where the Seventy Lost Djinn of Akhenaten are hidden.

After travelling around the world looking for clues, the book concludes with a battle in the British Museum, where the children must free their uncle by taking a trip to the North Pole.