That would be some of the lyrics from Devil's Waiting by the Black Rebel Motorcycle Club. Until this song was used in the season finale of season two of Hell on Wheels - I'd never heard of 'em. Shows what I know, I guess. Really, really like this haunting tune.
Here is a "live" version:
If you want to hear the album version, which is the one used in the finale, go here.
And finally, this is the last minutes of the season finale, where the song was used:
I'm not too sure this video will last - I'd bet AMC has it pulled. You can watch the episodes online - but that is mostly to rub it in Dish's face, because of the ongoing dispute they are having over programming pricing. AMC is "generously" allowing the shows to be seen so Dish customers can watch, too.
At any rate, just to explain (what I'm saying will be Greek to anyone who hasn't seen any episodes) - The Swede killed Lily, who by now is Cullen's squeeze. As you can see, the Swede wasn't shown dead, so my money is on him coming back next season. Great villain. Durant is in custody for fraud, Mr. Toole shot himself so now Eva is "free" to hook back up with Elam, who is the father of her unborn child. The encampment is destroyed and the population pretty well killed off. The Sioux won their battle, but at a severe cost. The episode was called "Blood Moon" and it was appropriately named. Things got mighty bloody.
If you have not seen any episodes, I highly recommend trying to catch some repeats or rent 'em. They're on iTunes and other similar sites, and Netflix has 'em as well. If you are close to me, I've even got season one on DVD as well. The series is very well written with some completely unexpected plot twists, and the acting is superb. The attention to detail seems authentic to the time period to me - the clothes, the tech, the language all seem authentic. It's good stuff.