This is the first book in the Midnight series by paranormal romance author Lara Adrian.

Lucan Thorne, a Breed warrior, would do what is necessary to protect the Breed, its people and their secrets. The world has no idea they exist and he wants to keep it that way. Even though his warriors had Breedmates of their own, he has no plans of finding one for himself. He was already hanging on the edge and wouldn’t want to take someone else down with him. Fighting a battle on the outside with the Rogues as well as inside himself, it was all about keeping things together. Another day of feeling his body slipping further and further into Bloodlust, he had no hope of [...]