Book 1

The Monstrumologist

by Rick Yancey

Published 22 September 2009

Book 2

The Curse of the Wendigo

by Rick Yancey

Published 1 October 2010
In 1888, twelve-year-old Will Henry chronicles his apprenticeship with Dr. Warthrop, a New England scientist who hunts and studies real-life monsters, as they discover and attempt to destroy the Wendigo, a creature that starves even as it gorges itself on human flesh.

Book 3

The Isle of Blood

by Rick Yancey

Published 13 September 2011
When Dr. Warthrop goes hunting for the "Holy Grail of Monstrumology" in 1888, twelve-year-old orphan Will Henry follows him to Socotra, plunging into depths of horror worse than anything he has experienced so far.

Book 4

The Final Descent, 4

by Rick Yancey

Published 10 September 2013
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 has been through more than seems possible for a boy of fourteen. He's been on the brink of death on more than one occasion, he has gazed into hell-and hell has stared back at him, and known his face. But through it all, Dr. Warthrop has been at his side.

When Dr. Warthrop fears that Will's loyalties may be shifting, he turns on Will with a fury, determined to reclaim his young apprentice's devotion. And so Will must face one of the most horrific creatures of his monstrumology career-and he must face it alone.

Over the course of one day, Will's life-and Pellinor Warthrop's destiny-will hang in the balance. In the terrifying depths of the Monstrumarium, they will face a monster more terrible than any they could have imagined-and their fates will be decided.

"Beyond a simple finale, this is a brave statement about the duplexity of good and evil, and the deadly trap in which all of us are snared" (Booklist, starred review).