"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...

When Apophis, the chaos snake, threatens to plunge the world into eternal darkness, siblings Carter and Sade Kane plan to use an ancient spell to destroy the snake, but first must rely on the murderous ghost of a powerful magician.

After a summer spent trying to prevent a catastrophic war among the Greek gods, Percy Jackson finds his seventh-grade school year unnervingly quiet. But things don't stay quiet for long. Percy soon discovers that the magical borders which protect Half-Blood Hill have been poisoned by a mysterious enemy, and the only safe haven for demigods is on the verge of being overrun by mythological monsters. To save the camp, Percy needs the help of his best...