The trailer for Nightwatch doesn't give much away about the story, but man is it creepy. It's a Russian-made horror film that only cost $4 million and according to the trailer it's the first of a trilogy.
That's creepy in a good, scary movie kind of way, not as in "Ewwww, I don't want to go see that."
If you visit the official site there is some more detail on the story... basically a long-running good-vs-evil truce is broken and the film deals with the consequences. The description reminded me just a little bit of Underworld, but the imagery in this film looks really scary and jarring, as opposed to the video game/wirework orgy that exemplified Underworld and Underworld: Evolution (BTW, I have a review on the sequel brewing in my head).
Anyway, check out the trailer for Nightwatch at the above link. It's opening soon, and I'm pretty sure I'm going to go check it out.