Since their mother's death, Carter and Sadie have become near strangers. While Sadie has lived with her grandparents in London, her brother has traveled the world with their father, the brilliant Egyptologist, Dr. Julius Kane. One night, Dr. Kane brings the siblings together for a "research experiment" at the British Museum, where he hopes to set things right for his family. Instead, he unleashes the Egyptian god Set, who banishes him to oblivion and forces the children to flee for their lives.

Carter and Sadie, offspring of the brilliant Egyptologist Dr. Julius Kane, embark on a worldwide search for the Book of Ra, but the House of Life and the gods of chaos are determined to stop them.

He's b-a-a-ack! Despite their best efforts, Carter and Sade Kane can't seem to keep Apophis, the chaos snake, down. Now Apophis is threatening to plunge the world into eternal darkness, and the Kanes are faced with the impossible task of having to destroy him once and for all.