Walker Kane didn't believe in monsters... Until they took his daughter.
Beneath Edinburgh's ancient streets, a prehistoric nightmare waits. The Grendsluagh—a creature of insatiable hunger—demands human sacrifice, and Walker's estranged daughter Emily has been chosen.
Desperate and haunted by years of failure as a father, Walker plunges into Edinburgh's deadly underworld. Time is running out, and Emily's terrified screams echo in his mind with every step into darkness.
He's not alone. A mythology-obsessed librarian who knows the monster's history joins his mission, along with a fearless urban explorer harboring dangerous secrets. Together, this unlikely team faces mutated horrors and a ruthless secret society protecting their ancient pact.
But the deeper they descend into the serpentine catacombs, the more Walker realizes the truth: to save the daughter he's failed so many times, he might have to become the very monster he's hunting.
Hero
Monsters
Dark Fantasy
Thriller
Survival
Adventure
Family
Conspiracy
Supernatural
Mystery
Redemption
Urban Fantasy
Folklore
Audiobook details
GenreMystery and Thriller, Horror
Length3 hrs 41 mins
Publish dateSep 24, 2025
LanguageEnglish
Table of contents
1Title Page
17Chapter 14
2Quote
18Chapter 15
3Prologue
19Chapter 16
4Chapter 1
20Chapter 17
5Chapter 2
21Chapter 18
6Chapter 3
22Chapter 19
7Chapter 4
23Chapter 20
8Chapter 5
24Chapter 21
9Chapter 6
25Chapter 22
10Chapter 7
26Chapter 23
11Chapter 8
27Chapter 24
12Chapter 9
28Chapter 25
13Chapter 10
29Chapter 26
14Chapter 11
30Author’s Note
15Chapter 12
31Closing credits
16Chapter 13
About the author
J. F. Penn
J.F. Penn is the award-winning, New York Times & USA Today bestselling author of thrillers, dark fantasy, horror, crime, and travel memoir. Her love for the macabre shines through in her writing, where she blends ancient myths with modern fears. When not crafting tales of supernatural suspense and otherworldly terror, Penn can be found exploring old graveyards, Gothic cathedrals, and indulging her morbid fascination with the darker side of history.View all audiobooks by J. F. Penn
