The use of the word "subtle" in the title is a bit misleading. This is basically an action story with vampires (created about 5000 years ago), the order of Thoth and a secretive organization, both of which are nominally there to rid the world of vampires, but each one seems to be just as interested in getting rid of the other. The vampires are extremely powerful and are hiding in plain sight, so their two opponents have not been very successful over the 5000 years.
The plot involves Anton Slayne, a student, who inadvertently invites a couple of vampires into his parents' house, and they kill his mother, abduct his father, but leave him alive. He runs (for no good reason), the police assume he is the killer, and after he has a few misadventures he runs into Gang, who runs "the Noodle House", and his daughter Li, both of whom are part of the Order of Thoth. Anton is trained and wants revenge.
Rodaughan prioritizes action over character, the action comes thick and fast, the writing is clear, and he writes very good prolonged action sequences. He has also read some arms catalogues, and the array of weaponry certainly raises the stakes, although whether you could use that in a city and remain unnoticed takes a bit of swallowing. The major vampire is Chloe, she is one really nasty character, and I found it rather odd that the characterization in this book was strongest for the females. Although I doubt you will like her, you will at least understand what is driving her.
It is also desirable to suspend belief, particularly in physics. At one stage, a vampire runs through the wall of a house. With the force necessary to smash standard framing, his chest bones should be fragmentized, but this is magic, and the rules are a bit unclear. The vampires are mainly active at night, but nobody things to have fluorescent lights that exactly mimic sunlight. Would that work? Who knows? This is the first of a series, and while it ends reasonably cleanly, it really leaves more questions than answers so there must be a lot more to this story. So if you want action, vampires, and do not want to think too deeply, you can't do much better than this. I have graded this on the basis that you may not want to commit to a series before reading the first book, and the grade refers to what I think it has reached at this stage. In many ways it reads like the introduction to much more. That much more may well be worth five stars, but at this stage, for me, it has yet to get there.