Tigris Eden 
Inferis (Shadow Unit, #5.5) 

The Shadow Unit has been disbanded, and the world as most know it has been thrown into chaos as the Defiant Ones wreak havoc across the Earth. The pieces are starting to fall into place, even as more questions arise. There is change on the wind and the sighting of an old member. Join Ronin and Belinda as they travel into the Underworld to rescue Royce. 
A Deal is struck…
Royce bargained his soul when he saved Dietrich’s sister, Yewa. He can’t return to the land of the living until his mate and brother come for him. But in the Underworld, everything has a price, and death comes in many forms. 
The race for Royce’s soul has already begun. 
The clock keeps ticking and time keeps moving, but nothing will stop his loved ones from rescuing him. 
Let the games begin.