Got this out of the library on a whim, found myself enjoying the book but not the experience of reading on Libby because holding my phone aggravates the arthritis in my hands, discovered the book was on sale for $1.99, bought it.
Kind of post-apocalyptic, in that something called the Merge has stitched together the Sidhe/Unsidhe and human worlds, with many unpleasant results including the appearance in the human world of monsters, such as the Black Dogs of the title. Our hero, Kai Gracen, is a Stalker, i.e. a bounty hunter of said monsters, who's apparently elfin but lives in the human world and has murky memories of a traumatic past. He has a gritty decency that I think he himself would deny, even despite the self-sacrificing heroism he shows during the climactic conflict.
[ETA: I should note, probably, that we find out a good deal about the tortures Kai underwent. They are imaginative and dreadful and might well be Too Much for a lot of people. In general, also, this is one of the darker and more violent books I've read lately.]
Kai's eventual love interest (though I gather they don't properly get together till the third or fourth book) is a Sidhe lord named Ryder, whose characterization I found somewhat less persuasive, in that he doesn't seem quite un-human enough despite his rank and his magical powers. I think the difficulty lies with his dialogue, which often struck me as too idiomatic for someone speaking what's in effect his second language.
The plot has to do with the retrieval, at Ryder's behest, of a pregnant human woman from a Sidhe city. In connection with this, one giant plot hole and one seriously annoying episode of childbirth. For once, it wasn't the childbirth itself getting on my nerves but rather Kai's reaction to it, including the hallowed line "Some things a man just wasn't meant to see," which oh come on.
I have to laugh at myself for being so peeved about this, given that pregnancy and childbirth are no-goes for me as well, but the idea that somehow it's especially terrible for a man to be exposed to it ground my gears. It seemed out of keeping with the rest of the book, which is full of interesting women characters (i.e., ladies are not gross), and also makes no sense whatever for Kai, who in the opening scene is up close and personal with the blood, guts, and general disgustingness of a Black Dog that he's hunting. He can deal with that, but labor is too much for him? Ohhh-kay.
I thought of putting the plot hole behind a spoiler, but it isn't much of one. The ruler of the city the pregnant woman is being retrieved from wants the offspring killed. But the ruler is, you know, the ruler, and a nasty piece of work even apart from the whole yen for infanticide, so ... how come she hasn't just had the pregnant woman killed? And, given that the woman is near term, why has Ryder waited till now to retrieve her? What's she doing in the elfin city to begin with? Et cetera.
Strictly on its merits I should probably have given this three stars, but I kind of had to go with four, considering that (a) I couldn't stop reading (b) I promptly bought the next two books in the series, which are also on sale for $1.99.