Sixteen-year-old Ash Fisher is the son of a vampire and a human, and as far as he knows, the only twin-blood in Black City. Because of his human blood he's allowed by law to live in the city proper, rather than behind the wall in the Darkling ghetto. He lives with his human father, making ends meet by selling his venom to human Haze addicts, and worries every single day, that this will be the day that the Trackers discover that he and his father are harboring a Darkling... a crime punishable by death. But how could they refuse? She's Ash's mother, and she's dying.
Sixteen-year-old Natalie Buchanan, meanwhile, is the daughter of Black City's Emissary: the woman in charge. The Buchanans have just returned back to the city after months in the capitol, a move precipitated by the savage murder of her father by a Wrath-crazed Darkling.
Full-blooded Darklings are barely second-class citizens; the few that live in the city are defanged and work as servants, and all of them—Ash included, despite his human blood—are required to wear ID bracelets at all times. ID bracelets that mark them as property of their human 'owner'. Not wearing the bracelets is punishable by death.
Any action judged a 'grievous crime against the state' is punishable by death, regardless of species.
Romantic relationships between humans and Darklings are punishable by death, regardless of species.
You've probably already guessed where the story is headed, and you aren't wrong: but that's not to say that there aren't some twists along the way. Since the prose stylings are neither squee-inducing nor remotely offensive, it'll be the plotting, the characters, and the world-building that attract or repel readers: and as Black City has a lot in common with other recent bestsellers, it should be pretty easy to figure out whether or not you should pick it up.
If you enjoyed the format of Marie Lu's Legend, then Black City might work for you: in this one, as in the Lu, the main characters alternate narration duties. And, as in Legend, the heroine is associated with the dictitorial government while the hero is, well, not part of the resistance, but certainly not held in any sort of esteem by the ruling class. Also, despite the vampires, I'd slot this one firmly in the science fiction arena.
If you like vampire apocalypse stories a la Emily McKay's The Farm or Julie Kagawa's The Immortal Rules and The Eternity Cure, then Black City might work for you: unlike both of those examples, in this case, the vampires are the subjugated class, but along with the action and the romance and whatnot, it deals with similar themes of racism and xenophobia. Black City actually takes that aspect of the story further, and makes some direct parallels to WWII with the aforementioned ghettos, with concentration camps, and with the ongoing experimental vivisection (i.e. torture) carried out in the name of research.
Like so many paranormal romances—though, as I said, this is more science fiction than fantasy—our characters do experience instalove, which I well know is definitely a dealbreaker for many. It, like Stephenie Meyers' 'imprinting' also turns out to be the sort of instalove that removes agency from the characters, which is another problematic element for some readers. In Richards' defense, she threw a hella-great twist into the mix of that plotline: even with the clues she dropped, I only saw HALF of it coming.
LONG STORY SHORT: WILL YOU LIKE IT? IT DEPENDS.
WHAT DID I THINK? Aside from a few issues—I found it bothersome that Natalie kept going on and on about how a Darkling killed her father, when she KNEW VERY WELL that that wasn't the entire story, because, you know, SHE WITNESSED THE WHOLE THING GO DOWN; the pacing got bogged down in the middle with all the 'DOES HE LIKE ME?' 'OH GOD SHE LOOKED AT ME AND I'D BE BLUSHING IF I COULD BLUSH' 'LET'S MAKE OUT' 'OH GOD WE JUST MADE OUT' 'IS OUR LOVE WORTH THE RISK?' and so on; there was some of that 'HE'S SO DANGEROUS BUT I LOVE HIM' that skeeves me out; the ex-boyfriend is such a complete d-bag that he comes off as a moustache-twirler—I approved of the plentiful gore and the creative vampire mythos (multiple species, various cultural traditions).
I'll be reading Phoenix to see where it all goes.
Book source: Finished copy from the publisher.