The Ring of Solomon is the last book in the Bartimaeus Sequence by Jonathan Stroud and the prequel to the trilogy.
Bartimaeus is enslaved by a dark magician who serves the great king Solomon in Jerusalem. He hates his service but knows there is nothing to be done. After all: Solomon has the Ring. And this Rings gives him great and terrible powers one can only dream of. If you were a magician, anyway. But then he saves a girl from Sheba, who changes his life in both good and bad ways. Continue reading