Books like The Dark Night of the Soul
St. John of the Cross
The Dark Night of the Soul is 224 pages, about 4 hours 6 minutes at 250 words a minute.
7 books to read next
How long each takes
The Way of Perfection 5.0 h 
The Interior Castle 4.7 h 
The Art of Detachment 7.5 h 
Liber Vitae Meritorum 5.5 h 
Seeds of Contemplation 3.6 h 
The Third Spiritual Alphabet 10.2 h 
Scivias 9.3 h Bar height shows length. Estimated at 250 words a minute.