Not that dark
When I first saw the title to this, I thought it was going to be something really sinister. While it did get that way near the end of the piece, it's actually more ambitious than anything else. It creates a good sense of mystery and intrigue. There's a real sense of atmosphere being created here as the sounds are so surrounding. I guess the last few seconds of silence prepare you for when it reruns. To a certain extent, it even seems reminiscent of film noir.
It makes me visualize something going around something to complete a journey. I can envision someone on the horizon in a story taking place in the desert. There are just so many themes you can make with a single song. There also seem to be layers build on the different kinds of instruments. It's simply a very active song.