In the fourth and final horrific adventure in the award-winning Monstrumologist series, Will Henry encounters unprecedented terror, a terror that delves into the depths of the human soul.

Will Henry

—New York Times Book Review, Editor’s Choice

“Dazzling tales from a master of the fantastic.”
—Washington Post

Two children, treasure map in hand, and their pet gazelle sneak past their father, out of their house, and into a world beneath the city, where monsters

The classic novel of angels, demons, and Armageddon from the internationally

Eleven thousand years ago, a god was born. Cursed into the body of a human, Acheron spent a lifetime of shame. But the strongest steel is forged from the fires of hell…

Acheron's human death

A Publishers Weekly Best Children's Book of the Year, Carnegie Medal nominee, and Book Sense Children's Pick.

Before The 5th Wave, there was The Extraordinary Adventures of Alfred Kropp. This first