An XPrize for you! I really like this - dark and mysterious, bayou at night. The depth of tone, the grain, the motion blur, all combine to make this a superb, disturbing, image.
I tried to find words, I really did. Like posthu, I was thinking charcoal -- or maybe chalk. But it was more about the end than the means. The overall impact bypassed the brain and went right for the gut. I couldn't call it ominous or sinister, but I couldn't call it calm or quieting either. Unsettling begins to unravel it, but there's a lot to unravel, and it's an understatement at best. To merely call it artistic seemed dismissive.
Well maybe I did find some words, but none that really get to the heart of the matter. And that's okay.