took us from bad to worse, leaving us with Castiel possibly becoming a turncoat and Sam being locked up by Bobby and Dean to detox form his demon blood addiction. Could things get worse? Of course!
Sam tries to talk Dean out of keeping him locked up, but Dean sticks to his goods and it's good that he does because not long after Sam begins to hallucinate. First, it's Alastair torturing him, then his younger self asking him why he ruined his life, his mother telling him she's proud of him and to not let her death be for naught and finally Dean, telling him he's a monster and no brother to him. Through all Sam's screaming, Dean and Bobby debate if they are doing the right thing or not.
Since there is no Demon Detox program in existence, Bobby isn't even sure that they aren't killing Sam to save him. Dean, on the other hand, would rather his brother die as a human than live on as a demon. Which sounds a bit cold until you consider that Dean spent a couple decades in hell being tortured by demons. And then he picked up the knife himself. Perhaps what he is really afraid of is that Sam will become what he was while he was in the pit.
Meanwhile, out in the real world, seals are breaking left and right. Dean screams for over 2 hours to get Castiel's attention, but the angel still refuses to tell Dean what he wanted to tell him back in Illinois. Instead, he demands Dean's loyalty and service to god and the angels in order to "spare" Sam. And even that sounds iffy, as Castiel says "If it gives you comfort to see it that way". Not exactly a ringing endorsement. Bobby doesn't think so either, but Dean defends his choice by stating that he would rather trust an angel than let Sam trust a demon.
Speaking of Sam, they have to tie him down as the detox process is flinging him about the room like a rag doll. Which is enough to make Dean want to hunt Ruby down before moving on the Lilith. Unfortunately, he doesn't get the chance as in the middle of the night, Sam's bonds come free, the door pops open and he escapes. And it's all thanks to Castiel. Anna confronts him about letting Sam go free, only to find herself taken into angelic custody as well. Thus it seems there may no longer be any member of the host they can believe in.
But it gets much worse. Dean goes after Sam, tracking him down to a honey moon suite where he nearly gets Ruby until Sam rescues her and she bolts. Sam tells Dean he's not strong enough to take on Lilith and that he knows what he's doing. Dean says that makes it even worse, because then it means that this is what Sam is. And when Sam asks him to clarify, it's his hallucination comes to life when his big brother answers "A monster". The Winchester boys had a knock down, drag out fight, where Sam comes out on top and Dean tells him that if he walks out the door he can never comes back.
And Sam walks.
This can't be the end of the Winchesters, can it? What would you think if we saw Sam defeat Lilith but turn into the full fledged monster Dean fears and must hunt? Dean was taken out of the pit, but is he still looking for redemption? And has Sam given up on such concepts in his search for vengeance?