Bound by Darkness (The Alliance, Book 3) - The Alliance, #3

Determined to rescue Simone from the vampires who took her, Killean must become the thing he's spent his life fighting-a Savage. As he sinks further into a world filled with death, Killean struggles against his growing bloodlust as he vows to do whatever it takes to save Simone from becoming a monster like him. The day Simone looks up and sees Killean in her prison, she believes she's imagining things.
Then she realizes that the vampire whose kiss made her feel so alive has succumbed to his darkest urges and is now one of the things holding her captive. When Killean tries to rescue her, Simone learns things aren't what they seem. Fleeing into the night, they discover Savages breathing down their necks at every turn and soon realize they must work together to survive. However, even if Killean can save her from the vampires hunting them, can she save him from the darkness devouring his soul?***The Alliance Series is a spin-off of the Vampire Awakenings series.
You do not have to read the Vampire Awakenings Series to follow the Alliance Series. Due to violence, language, and sexual content this book is recommended for readers 18+***