Used Book – Vampire Earth, Book 2: Choice of the Cat, E.E. Knight

55th year of the Kurian Order. Lieutenant David Valentine is proud to serve in the Wolves, an elite caste of warriors dedicated to retaking Earth. But after a disastrous battle, Valentine is court-martialed and forced to resign. He then enlists in the Felines, a caste of spies. His first mission is to infiltrate the Kurian Zone, deep in enemy territory, to learn more about the Twisted Cross, an organization of hybrid fighters who possess the warrior skills of the best veterans and the morbid voracity of the Reapers...