There are many times in a man's life when he finds himself contemplating his future. Dean just so happened to be thinking about just that as he stared down at the grass in front of him. The same patch of grass that had just so recently been a giant hole in the ground that he just saw his little brother take the swan dive into, along with who happened to be the Archangel Michael. He has done so many things in his life, he's killed hundreds of monsters and demons, including the one that killed both his parents, saved countless people, and hell he has now even stopped the God damn apocalypse. But as he sat there on the grass in the middle of that godforsaken cemetery, a single thing ran through his mind: "What now?"
Sam was gone. Bobby was gone. Cas was...well...in bits and pieces. He was all by himself, starring down at the same patch of grass. His face hurt like a bitch and he was pretty sure a few of his teeth are loose, but the rest of him just felt numb. It didn't quite feel real. Had all of that really happened?
He didn't know how long he'd been sitting there but he figured long enough because the sky was starting to darken and his legs had fallen asleep and were screaming at him to get up and move. He shakily climbed to his feet and as he stood he noticed something he didn't before, something glinting in the setting sun. The rings.
Hesitantly, he staggered over and picked them up, twirling them around in his fingers. Again the question that went through his head was: "What now?"
He looked over his shoulder to see Bobby's still form and the bloody patch of grass that was once Cas.
A few hours later, the fire from the Hunter's Funeral he gave Bobby was dying down as he walked back to his Baby. Upon inspection it was only little banged up from his little throw down with Lucifer (Dean being the one that was thrown). Later, he decided, he'll fix her up later. Still, he was numb. No tears, no sobbing, no cursing God's name, well actually he was doing that, but the point was, he felt like something was off. He had every right to be laying on the ground in the fetal position crying his eyes out like a little girl, but he wasn't. Instead he climbed into the impala, radio off, and just drove.
He didn't think about where he was going, despite the constant chorus of 'what now' playing through his head, he just picked a direction and drove. After a few hours he pulled over at a cheap motel, paid for a double room (force of habit), and sat down on the corner of the bed closest to the door (another habit from years of following the mantra of "protect Sammy").
He pulled out a bottle of Hunter's Helper that he bought the day before out of his duffle, he didn't bother to find a glass. It wasn't that he really had felt the need to drink himself under the table, but he decided he might as well, after all it was tradition after a horrible Winchester-grade tragedy, and today he lost his brother, his adoptive father, and his best friend, everyone he had left. It didn't take long before Dean was passed out on the end of the bed, lack of sleep and watching your whole family die within the span of a few minutes will do that to you.
4 hours of sleep and a wicked hangover later Dean was back on the road again. He didn't have anywhere else to go so he set course for Sioux Falls, South Dakota.