Realm of Darkness: Infernal Three, Volume 1 (Unabridged‪)‬

He's the rising star of the Paranormal Investigation Agency; she'd love to burn it to the ground. 

Tria Winters plays the part of the loyal agent well, but she's nothing short of a prisoner. When the Agency is brutally attacked, she and her cousins should have taken their chance to run, but to her surprise, there are people she isn't quite willing to turn her back on. 

It's obvious to Gray that Tria and her family are trouble, but they're the only ones able fight off those who destroyed the Agency. He needs to stay with them. 

Even though their plan may land him in Hell.