Meanwhile, somewhere else in Wyoming
To Sam, finding Dean was the most important thing in the world right now. Chuck had said that Dean hadn't said yes to Michael yet, but that didn't mean that he wasn't close to doing so. For all Sam knew, his brother was talking to Zachariah right now, negotiating everything that he was and ever would be away to a higher being that honestly didn't care about any of them. How could he have? Zachariah helped start the apocalypse. As far as Sam was concerned, the son of a bitch was only in it for the thrill and glory, not the actual righteousness of it all. He didn't care who got hurt in the crossfire. Who got sacrificed. Knuckles going white against the steering wheel, Sam pressed down on the gas harder. The scenery surrounding him whizzed by even faster - not fast enough for Sam's tastes, since he'd rather be at Dean's doorstep now, but it was the best he could manage.
At least it was until he reached the meeting place Castiel had pointed him to. Working with Cas, the way he saw it, was the best way to go about this situation. Castiel would pop them both over to Dean, Dean would try to pull his angel banishing trick again (something that Sam was hoping to be quick enough to stop his brother from accomplishing, since he was pretty sure that Castiel was getting tired of having to locate and relocate himself over and over again), then Sam would be left behind. With Dean. He didn't know how things were gonna go down after that. Maybe Dean would reluctantly agree to go back with him. Maybe Sam would have to fight his brother, beat him down until he couldn't run anymore altogether.
Sam hoped he didn't have to go there. He didn't want to. What would he do if Dean didn't want to go back? What if he couldn't talk sense into him? Where would Sam take him? What would they do with him? Hold him hostage against his own will? Refuse to let him see the light of day again until he agreed not to go running to Michael the second that they let him go?
Anxiously, Sam rubbed at the back of his neck, long legs carrying him to his and Cas' meeting place once he parked in a suitable location. Reaching the door, Sam gave it a sharp knock, shoved his hands into his pockets, and glanced over his shoulder uncomfortably. They'd deal with this. They had to.