Youngblood (Babylon Hunters #1)

Babylon City’s newest Hunter, Gideon Caldwell, is on the trail of a vampire serial killer—until he stumbles upon a far deadlier threat to the Contract, the ancient pact keeping supernaturals hidden. Something dark brews in the city’s bowels, reeking of sulfur and death. But Gideon’s biggest problem isn’t the case—it’s Cor, his unexpected vampire sidekick: sexy, dangerous, and utterly off-limits. More beast than man, and worse: he’s very much interested in Gideon.
But Hunters don’t get the picket fence life. Never. Especially not with the enemy. Cor, on the other hand, has no such qualms…
As lies and intrigue tighten their grip, Gideon must unravel the conspiracy in time to save the one supernatural he is terrified to lose.