There's a momentary hint of relief at finally knowing what the price is going to be (and knowing when it'll be over, too -- it's not that long a wait), but it's hastily swallowed up by the sick feeling in his gut.

Because a year isn't much time at all, and Sammy -- Sam's going to be coming back to almost less than nothing. Except --

Except if Dean doesn't do this Sam isn't coming back. And if Dean's gonna be damned either way --