Spoilers : Somewhere Between Heaven and Hell 12.15 Synopsis + Photos
Official Synopsis from the CW: "An attack by an invisible hellhound at a campsite leads Sam (Jared Padalecki) and Dean (Jensen Ackles) to investigate the mysterious circumstances. Meanwhile, two of Crowley‘s (Mark A. Sheppard) own personal demons uncover what he has been hiding. Castiel (Misha Collins) gets a lead on Kelly Kline."
Photos here:
http://www.buddytv.com/slideshows/supernatural/supernatural-episode-1215-photos-will-lucifer-escape-59353.aspx
I see Lucifer without his chains. No bueno.