Books like Lord of Sin
Madeline Hunter
Lord of Sin is 406 pages, about 7 hours 27 minutes at 250 words a minute.
6 books to read next
How long each takes
The Hidden Heart 7.6 h 
The Saint and the Sinner 3.1 h 
Dukes Are Forever 6.8 h 
A Worthy Pursuit 7.7 h 
Four in Hand 5.5 h 
Love's Folly 4.6 h Bar height shows length. Estimated at 250 words a minute.