When Philippa and John discover that they are djinn, with the power to grant wishes and do magic, their days of living as just plain children are over!

Philippa and John are twins, although they couldn't look less alike. John is tall and thin, with straight brown hair. Philippa is short with wavy red hair. But inside their heads, they think remarkably alike, and can even finish each other's sentences. Their parents are just as unalike as their children. Layla is six feet tall with an athlete's body, while Edward is just five feet, with grayish hair and tinted glasses. But the four of them are very happy in their large, comfortable house in New York.

The summer Philippa and John are twelve, they go to the dentist for a regular checkup, and he discovers that they've both grown their wisdom teeth. Since that shouldn't have happened until they were adults, their mouths are way too small for four more teeth, and they will have to be removed. That means general anesthesia and a visit to the hospital, and while they are unconscious, the twins have the most extraordinary experience of their lives.

It's like they are sharing a dream, walking along a river that runs down to the sea. And there, floating above the waves, is a Middle Eastern looking palace. A man opens a window and introduces himself as their Uncle Nimrod from London. He is tall, dark, dressed entirely in red, and very excited to be seeing Philippa and John again. He invites them to visit him in London for the summer instead of going to summer school. Their parents will let them fly over by themselves if they just tell their mother that they want to. But Uncle Nimrod doesn't really explain why their mother won't say no, or why it's so important for them to come to London immediately, or why he and Layla haven't spoken since the day the twins were born.

When they arrive in London, their uncle, still dressed in red, is there to meet them. He explains why their mother let them travel alone, why unexpected things happened to them at home and on the plane, why they had grown their wisdom teeth so early, and why they could suddenly read a thousand page book in just a few hours. All these things happened, explains Nimrod, because they are descended from a long line of djinns on their mother's side — their mother is a powerful djinn herself — and their powers began when their wisdom teeth were taken out. Uncle Nimrod has brought them to London so he can teach them how to use their new powers. Or at least that's what he intended to do. But an earthquake in Egypt, a crack in John's bedroom wall back home, and a shift in Uncle Nimrod's luck have changed all that.

When the universe was created, the angels were given dominion over heaven, humans were given dominion over the earth, and the djinns were given dominion over the interaction between the two. Men thought it was based on chance, and called it Fate. But the djinns knew that it was really based on a very careful balance of good and bad luck, controlled by good and bad tribes of djinn. Somehow the earthquake tilted the luck meter to the bad side, throwing it off-balance, and Uncle Nimrod has to go to Egypt and find out why. And of course, he takes Philippa and John with him, to give them their first lessons on how to use their djinn luck when and where it will do the most good. And they are going to need all the luck they can get, because they will have to fight Iblis, the most evil djinn in the universe, and if that universe is going to survive, they will have to win!