The Golem's Eye

The second adventure in the Bartimaeus trilogy finds Nathaniel working his way up the ranks of the government, when crisis hits. A seemingly invulnerable clay golem is making random attacks on London. Nathaniel and Bartimaeus must travel to Prague to discover the source of the golem's power.
In their continuing adventures, magician's apprentice Nathaniel, now fourteen years old, and the djinni Bartimaeus travel to Prague to locate the source of a golem's power before it destroys London.