I am so conflicted about the whole Jack In the Box thing! Yes, Jack was manipiluated by Duma into doing horrific things, but he thought he was doing God's work and that Sam and Dean would be proud of him. Yet if he's that easily manipulated and capable of inflicting such horror, he shouldn't be out in the world. So I can understand them wanting to keep Jack locked away, but not in that awful box, and despite how he referred to Mary's death as 'the accident' I still think they could have reasoned with him and made him realise he's on the wrong path. I was pretty horrified that they manipulated Jack into agreeing to go into the box, his trust in them and desire to please were heartbreaking. However, I think Dean would've killed anyone else who showed so little remorse, and as he can't kill Jack, this was his solution; I also think that from Dean's POV, he built the box to bury himself alive to save the world, and he thinks this is therefore something Jack would agree too! But despite all this, I loved this episode for the scene with Dean crying. Oh boy, Jensen outdid himself with the sobbing, just perfect.