Dave is a self-centered racist sexist homophobic jerk who just spent his holiday bonus on top-flight hookers instead of paying his wife the child support money that she needs to feed and clothe his two sons. He's also the chief safety engineer on a deep-drilling BP oil platform in the Gulf of Mexico that somehow manages to open a portal to the "Underworld", freeing a troupe of demons to slaughter and eat Dave's co-workers. When Dave stumbles upon a "Hunn" chowing down on one of his friends, Dave becomes so enraged that he somehow manages to kill the monster, thereby acquiring magical powers.
The creatures of the Underworld, it turns out, used to prey regularly on humans, but many millenia ago they were forced underground (or into another dimension; it's not entirely clear) by the "Sky Lords." Now, perhaps because of deep sea drilling, the boundaries between the Underworld and the human world are wearing thin. The Underworld demons are formidable enemies who'd love nothing more than to disembowel us and eat us alive, but, on the other hand, the Iron Age weapons that once served them so well are now a bit dated.
Even if their weapons aren't au courant, the demons have brute strength and unquenchable ferocity on their side. Can humanity keep them in check? Not without Dave.
That's OK. Sometimes we need a superhero, even when the superhero is also a super jerk.
What's worst about Dave is not that there's so much to despise about him, but that the author seems to think (a) that the audience will see Dave as an average working class Joe [and, I should add, perhaps this *is* how Aussies like Birmingham see the average American man], (b) that the audience will identify a bit with Dave's unsavory views (particularly those having to do with "banging" women) even if they wouldn't dream of acting or talking like Dave, and (c) that the audience will forgive Dave his jerkiness once he comes to his senses and starts acting less like a hedonistic monster and more like a human being. (This does not happen in Book 1, but there are many hints it will happen by Book 3.) At least that's the impression I get from the politically correct undercurrents that seem to run through Dave's mind even while he's trashing people.
There are also problems with the way a working class African American portion of New Orleans is portrayed in the final chapters of the book. People talk funny, they do stupid things, and the only prominent local character is a gang leader.
So, Birmingham may have problems with racism, sexism, and homophobia, but if you can forgive that, he does succeed in other areas. Though the plot evolves way too slowly in the first half of the book, it does eventually pick up steam. The world building is not terribly original, but it is effective. In particular, Birmingham does a reasonable job of giving his demonic characters alien modes of thought without making those modes of thought opaque or silly. There's nothing magical about his writing but he is perfectly capable of stringing together readable sentences and paragraphs -- a feat that many published authors today can't seem to manage.
What's the bottom line? I feel dirty saying this, but I'm actually interested in what happens next. I absolutely would not recommend this book to everyone, and if you're a racist sexist homophobe the most polite thing I can recommend is that you go get your head examined. So, I guess I won't recommend it to anyone. Caveat emptor.
Note: I received an advance copy of "Emergence" via Netgalley.com in exchange for an honest review.