The Ring of Solomon — Jonathan Stroud

Bartimaeus, everyone's favorite (wise-cracking) djinni, is back in book four of this best-selling series. As alluded to in the footnotes throughout the series, Bartimaeus has served hundreds of magicians during his 5,010 year career. Now, for the first time, fans will go back in time with the djinni, to Jerusalem and the court of King Solomon in 950s BC. Only in this adventure, it seems the great Bartimaeus has finally met his match. He'll have to contend with an unpleasant master and his sinister servant, and runs into just a "spot" of trouble with King Solomon's magic ring....