Except that he doesn't make a living at it, really. Like all good urban fantasy MCs (and don't listen to the folks who tell you this is horror because there are ghosts in), Castor is broke. UF protagonists are perpetually short of funds, often because the rent is high or they can't charge what they'd like or their weapons don't come cheap. Quite often when I run across one of those excuses, I twitch. It's been done. It's cliché. The writer isn't trying to be creative about it. But it was different with Castor because his reasons for being broke feel more valid.
- A year and a bit ago, he did a job that turned out not to be what he thought, and it's shaken his confidence and made him scared to take more clients. Therefore, he has no money because he has no income.
- His landlady, who's also a good friend, is constantly coming up with get rich quick schemes, which need startup fees that Castor helps her out with, because he's that kind of guy. And that's more or less on top of his rent money to her.
So basically, Castor has negative income not because Carey's playing to the trope as much as because it's part of his characterization and motivations. He only takes the job that's the central plot of the novel because his landlady needs money now and he doesn't have anything to give her. I'm much more willing to forgive this than I am to forgive the protagonist who, say, needs the downtown condo because it's so close to her favourite restaurant.
And there's another trope that features in Devil You Know that I only really noticed because I've seen enough blog posts to know it's a trope. How do you string out a plot when a key piece of information is a phone call away? You make it hard or impossible for your protagonist to use their phone. I've read a lot of urban fantasy in which phones get lost or smashed or dropped in water, repeatedly. I've read some, I believe, in which phones get covered in the bodily fluids of monsters. Castor's phone, on the other hand? Is faulty and he can't afford to get it replaced because … he's broke. So sometimes the phone works just well enough for a scratchy connection, and sometimes the phone will show "no signal" while he's standing under a tower. Much more plausible, in my books. It's obvious Carey put some thought into this story—which is to be expected, since he's won multiple awards for his comics.
There are other tropes in the book as well: people trying to kill Castor, people having sex with Castor, Castor getting up and continuing the case after nearly dying, Castor being chided for being thick-headed. If you read urban fantasy, you've seen these before. If done poorly, these tropes are enough to make me want to hit the MC or writer over the head with the book they're in. If done well … well, I'm not rushing out to get the second book in the series, because I don't like reading two books by the same author back to back, but Carey's books are definitely going down as "good reads", "well-written", and "TBR list". I can't wait for him to impress me again.
*If you read my summary of my 2010 reads last week, it was one of two books I started last year but hadn't finished by the end of it.