This track is characterized by a haunting windlike sound—not quite as monotonous as white noise—overlaid with dripping water, the occasional metallic creak, and rats skittering about and chittering to one another. That's about it. It's dark and desolate, as an abandoned subway tunnel should be. Of course, it doesn't have to be a subway tunnel that your PCs are moving through; this track could just as easily spice up a sparsely-populated fantasy dungeon of the good old "dungeon crawl" kind. I do think the wind/white noise might be a bit too heavy, though. It makes me wonder where that wind is coming from.