It's a war between the dark and the light when the Darkness is free from her cage, and Sam and Dean Winchester, Castiel and Octavia the Angels are the only ones trying to stop it, and trying to stop at any means necessary. Even when Lucifer gets involved. They've long since learned that the dark and the light are crossed at blurred lines, and that line keeps getting more in question when it's targeted at one of them.
34 parts