Apophis, the serpent of Chaos, is free of his prison in the Abyss and gaining strength. His rise could mean the end of the world. Carter and Sadie Kane think they’ve found a way to send him back into the depths of the Duat, but they’ll need help.

They won’t get it from the sun god Ra. The once great and powerful king of the gods has turned out to be a pajama-wearing lunatic. They lost Bes, the loyal and incredibly ugly dwarf god, in a game of chance that went horribly wrong. Their uncle Amos has his hands full with a renegade group of Egyptian magicians who seek to take over the House of Life. And their best magician—and best friend—Walt Stone is dying of an illness that not even their top healer Jaz can cure.

Still, Walt refuses to let Sadie and Carter face the deadly challenges ahead without him. First up? Saving a special scroll, aptly named the Book of Overcoming Apophis and housed in a museum in Dallas, from being destroyed. They’re on their way to get it when Sadie is waylaid by a mysterious face peering out at her from a wall. The face tells her to forget the scroll and go for the golden box instead. Then it vanishes.

Sadie is troubled, but keeps their goal in mind. But just as they get their hands on the papyrus, Apophis’s forces attack. The museum explodes into flames—and so does the scroll. At the last second, Sadie spies the small golden box the face told her to take. She snatches it up and flees with the others through the Duat back to Brooklyn House. There, she opens the box to discover…nothing. It’s completely empty, a dead end.

Or is it? The box is what’s known as a shadow box, created to hold the shadow, or sheut, of one who has passed on. The idea of a sheut as a separate part of a being strikes a chord with Sadie and Carter. Perhaps there is a way to defeat Apophis by capturing his shadow. If they’re right, they’ll need to perform some seriously dangerous magic to make it work. There’s only one scroll that holds that kind of magic: a copy of the Book of Thoth, annotated by Setne, an evil magician who died centuries ago.

Luckily, Carter and Sadie have a special relationship with the god of the Underworld. He’s their dad, after all. But will Osiris allow the magician to leave his realm? And if so, can the Kanes trust Setne to deliver the book and not kill them instead? And where, exactly, will their quest lead them?

There’s no time to worry about that now. Apophis will rise in three days…