After their father's research experiment at the British Museum unleashes the Egyptian god Set, Carter and Sadie Kane embark on a dangerous journey across the globe--a quest which brings them ever closer to the truth about their family, and their links to a secret order that has existed since the time of the pharaohs.

In this adventure, Annabeth encounters more oddities in the subway than usual, including a two-headed monster and a younger blond girl who reminds her a little of herself. This is the story fans have asked for, in which Annabeth Chase teams up with Sadie Kane. The demigod daughter of Athena and the young magician from Brooklyn House take on a larger-than-life foe from the ancient world. Perhaps even more disturbing than the power-hungry god they encounter...