First some honorable mentions in no particular order

Eerie scene. The white figure with the very dark trees in the background evoke a ghost

Hitchcock, here we come!

The deliberate underexposure works. That water looks threatening for sure. Don't get too close to it.

Lights across a hazy swamp... Probably elves, but who knows? The motion in the image is really interesting.
Third place

Stark black and white. And yes, the sadness comes through.
Second place

A strong image of futile struggle and death. Truly dark.
Fist place/winner

I liked this one right of the bat. Not sure what was done here technically, but the effect is strong. A faceless human in some sort of web... Yikes!