Great cover here, it definitely is intriguing. I think part of the mystery is added by the fact that there isn't an individual directly on the cover. The shadow of the wolf is great, and the gleam of light on the metal is really great, I'm super impressed that this is your first time drawing metals that close up. I would have assumed you had done it a bunch of times, judging from the execution here! Way to go!
Once again, your book covers rise head and shoulders above at least 90% of what I see on bookstore shelves. The sheer size of the locket immediately grabs your attention, but it's the subtle touches of blood and the canine shadow that really sell it. I'd grab this one off the shelf for sure.