Carter and Sadie are taken to Brooklyn by their uncle Amos, who tells them they are descended from a long line of magicians, beginning with the Egyptian pharaohs Ramesses the Great and Narmer. He also explains the grave danger Set poses to the world, and goes to find him. While he is away, the mansion is attacked by Set's minions. With help from Sadie's cat Muffin, who is host to the goddess Bast, and Zia Rashid, they escape to Cairo. Once there, Carter and Sadie discover they are hosts to the gods Horus and Isis, respectively. They train in magic until the magicians' leader Iskandar dies and Michel Desjardins orders their deaths for collaborating illegally with the gods. The siblings escape and formulate a plan to defeat Set — hoping to rescue their father and clear their names within the magic community. They travel to Set's lair in New Mexico, gathering ingredients for a magic spell and evading hostile monsters and magicians. Desjardins summons Sekhmet who destroys everything in her path until they stop her by tricking her in eating excessive salsa.