In a nutshell, the book has Gaby (Gabrielle Cody) getting vague messages/feelings from 'God', and goes forth to vanquish the evil God sends her (in the way of knife slashing and viciousness). There's a not-so-plucky assistant/punching bag named Mort, and along the way she meets a cop, Luther Cross, who spends his time following her around and emanating sexual tension (apparently). It's an all right premise (sorta), made terrible by the characterization and execution.
I ended up disliking the main character, Gaby, so much. There are strong heroines, and then there are characters like Gaby, who seem strong, but are verbally abusive, physically abusive, and an all around jerk. Yes, she has a crappy job from hell (well, heaven). Yes, she needs to go out and kill unspeakable evil (providing that she's just not bugfuck crazy). But does that really excuse her behavior? She's horrible to her landlord, Mort. Then she seems to drag him along with her and become her accomplice in crime (not willingly, but considering how much the guy tries to help her out, you'd think she'd at least be civil to him). She physically attacks several people, who, all right, seem to be begging for it, but there's a line between self defense and excessive force that she crosses seemingly unable to even see it. Anything that doesn't go her way she reacts with her fists. It's appalling that this is your heroine that you're supposed to like or relate to.
She has a thin veneer of toughness over loads of melodrama and irritating weakness (which should make her more relatable, but makes me want to smack her). Then she excises this by drawing/writing graphic novels that are a underground cult hit. Seriously? She's apparently completely naive in sexual matters (she asked Mort and then Luther about oral sex, I kid you not--she should at least have known that that is not something to ask your not-friend about), and I'm supposed to believe this? From a girl who lives in a really horribly crappy part of town, and who grew up in foster care and should have at least some peripheral awareness? Though she doesn't listen to music and has never watched tv in her life (or something). Her character is horribly put together.
Luther Cross isn't much better. He's a 'man's man' who gropes Gaby. He does have a moment of 'why did I do that?!', but that doesn't excuse him. One wishes he was more professional and less, 'I want to get into her pants so badly'.
The most likable person, in my opinion, is Mort, and he's an irritating hanger-on, who doesn't seem to realize that maybe he should butt out of other people's business. But then horrible things happen around him and you think to yourself, 'poor guy', so maybe he's more of someone to pity than someone to actually like. Who knows.
The way the book is written isn't much better. Very dramatic (overly so). I rolled my eyes at a few phrases and the melodrama.
In a market glut with urban fantasy, you'll find dozens of books better than this one.