Books like The Keep (Adversary Cycle)
F. Paul Wilson
The Keep (Adversary Cycle) is 416 pages, about 7 hours 38 minutes at 250 words a minute.
12 books to read next
How long each takes
The Reader 3.8 h 
Diaries 9.0 h 
The Atrocity Archives 6.2 h 
Lilac Girls 9.4 h 
Sarah's Key 6.5 h 
Operation Paperclip 11.3 h 
Rozmowy Z Katem 7.6 h 
HHhH 6.3 h 
The Scarlatti Inheritance 6.7 h 
The Huntress 10.3 h 
The Holcroft Covenant 9.1 h 
The Valhalla Exchange 5.1 h Bar height shows length. Estimated at 250 words a minute.