Lyric discussion by cwsaxygirl13 

Cover art for Howling lyrics by Abingdon Boys School

I don't know about the rest of the song, but I think the beginning speech fits perfectly with Darker Than Black. The mysterious assassins and killers. The contracts the appropriately named "Contractors" are bound to. And the Gate that encircles the entire city, obviously holding a secret. Hmm...I wonder if this song was written just for that show.