"So his soul is trapped inside a cage in Hell. Why wasn't it able to come back, is there something on the cage preventing it?" Evie asked, unaware of what the true purpose of the cage was and the terror which lay inside. Sam pulled his shoulder away from Cas' hand after he spoke, glaring before Evie talked about the cage. 

"Not something, [i]someone[/i]. Lucifer. The cage I foolishly opened, releasing him upon the world. I agreed into becoming his true vessel to trick and trap him in the cage again along with Michael." He explained before going quiet.