The Bureau: Volume 1. The Bureau, #3.1

This collection contains the first three Bureau novellas:  CorruptionOnce a proud demon of the night sky who carried nightmares to humans, Tenrael has spent decades in captivity as the star attraction of a traveling carnival. He exists in miserable servitude to men who plunk down ten dollars to fulfill their dark desires. Charles Grimes is half human, half...something else. For 15 years he's worked for the Bureau of Trans-Species Affairs, ridding the country of dangerous monsters.
When his boss sends him to Kansas to chase a rumor about a captive demon, Charles figures it's just another assignment. Until he meets Tenrael. Clay WhiteSomeone - or something - is murdering young men in San Francisco. Clay White has been fired from the Bureau of Trans-Species Affairs, but he's determined to track down the killer. When he comes across a vampire named Marek, Clay assumes he's caught the perp.
But the encounter with Marek turns out to be more complicated than Clay expected, and it forces him to deal with his own troubled past and murky psyche. As Clay discovers, sometimes the truth doesn't come easy - and the monsters are not who we expect. Creature Alone in a cell and lacking memories of his past, John has no idea who - or what - he is. Alone on the streets of 1950s Los Angeles, Harry has far too many memories of his painful past and feels simply resignation in facing his empty future.
When Harry is given a chance to achieve his only dream - to become an agent with the Bureau of Trans-Species Affairs - all he has to do is prove his worth. Yet nothing has ever come easy for him. Now he must offer himself and John as bait, enticing a man who wants to conquer death. But first he and John must learn what distinguishes a monster from a man - and what a monster truly wants.