Matthew W. Harrill 
Hellbounce [EPUB ebook] 

Prison psychologist Eva Ross has dealt with her share of sinners. The corrupt, the insane; their minds were hers to unlock. But when those around her start to show the same characteristics, she is forced to turn to a stranger for help.
Together with the mysterious Madden Scott, Eva enters a new reality. As the world around her shifts, secrets barely hidden under the surface are revealed.
In an adventure that takes them through nightmares and across continents, Eva and Madden enter the shadowy world of Anges de la Resurrection des Chevaliers: the last barrier between earth and what lies beneath.