I must confess that I'm not really up on my Werewolf lore; I've seen some of the movies, of course, including one with Abbot and Costello, but I'm going to trust you to have the terminology and rituals correct. In any event, they're irrelevant to the issues I want to address.

Let's keep it simple: you have one job as a writer and one only, which is to be read. If you don't have readers, you're playing solitaire in the dark. So whatever else you do, wherever your inspiration takes you, you have to keep the readers turning the pages, which means you have to keep them asking that most essential of questions: "Gosh, I wonder what's gonna happen next?"

If they're asking that question, that means that, however you structure your characters, their conflicts and the plot that evolves from them, things are in doubt, the status quo is out of balance and your characters are seeking something they don't now have, or they're trying to avoid something. I think you have a handle on all this Plotting-101 stuff, in terms of the grand arc of your story, though I have no idea yet what it might be. What you need to realize, however, is that you need to bring this sensibility to every element you put in front of the reader. Every scene needs an arc, everything that happens needs to be a problem that requires decisions and actions. Everything, in short, needs to be a story.

You can make stories out of anything: crossing the street in busy traffic, fumbling for your house keys at two in the morning after too much partying, trying to cook breakfast, looking for a gas station in a strange town. You just need to keep asking yourself, not "Who are these characters?" (they can sit motionless in a chair all day long and be who they are) but "What is it that is putting them in motion?" And, of course, the aforementioned "What do they need? What are they running towards, or running away from?" You have two passages that seem to me to sum up the flaws in your approach.

After George dies, and Des is trying to prep Ruby for the drastic shift in her life circumstances, there is this sentence:

She’s done more talking in the past ten minutes than she has in all her twenty-three years, it feels like. At any rate, they have to get out here before more trouble shows up.

It felt that way to me too, truth be told. After a pretty decent opening scene, Des and George descend into the Valley of Yadda Yadda Yadda where your story dies along with George. Rule of thumb: most backstory is unnecessary. What is necessary is to have characters involved in their stories (reference the previous stuff about problems, decisions and actions), and acting consistently with their backstory. Toss a reasonably intelligent reader into the mix, one capable of drawing conclusions and making educated inferences on their own, you can go far with little.

Any details from the past that are truly essential can be slipped in sideways at appropriate points where the action would naturally lag—pausing to light a cigarette, waiting for an elevator to reach the 15th floor, riding uptown in a taxi. Each of those situations would offer different opportunities for exposition, depending on how long the moment itself would last in the present. Lighting a cigarette might be an occasion to reflect about an unanswered question, whereas riding uptown might be an occasion for a much longer stretch of narrative. But any time you make your characters talk about backstory, it's just an info dump, forcing them to say things that wouldn't really need to be said in a real interaction. So go for those interactions, make them consistent with what you already know about where they've come from and how they got here, and focus on making sure your reader keeps turning the pages.

The other passage that raised a red flag is this one:

By cloudy, drizzling midnight, Des was exhausted from carrying Ruby around and keeping to the shadows and alleyways. They were both drenched (which at least muddled their scents in case someone came sniffing after them), and Ruby was coughing rackingly.

Did you notice the entire chapter that was compressed into those two quick sentences? I'm not sure what problems Des might have faced, in the course of becoming exhausted, but I'll just bet you could have made the odyssey interesting. Also, this is the second time you've threatened trouble, only to do nothing about it. The first is in the previous passage I quoted, where you observe that they need to get going before trouble shows up.

Dude, to paraphrase a Chandler short story title: Trouble Is Your Business. No trouble, no story.

I don't need to beat you over the head with this. You're a good writer and your problem isn't the sound, shape and sense of your words. It's how you're using them, the narrative choices you're making. Well, I take that back. You need to decide if you're going to tell this in present tense, or past, and stick to it. There's no way you'll ever be taken seriously if you keep rambling back and forth they way you are now. Also, rethink that cough of Ruby's. If you need to turn an adjective into an adverb (rackingly? Really?) it's time to rewrite the sentence. Maybe let cough be a noun. A hacking, or even a racking cough gets the job done much less clumsily (See? Those adverbs just never sound right).

I think you can turn out a good product. Just dump the info dumps, and don't be afraid to actually give your characters a story. That should do it.