What would happen if Dean never visited Lisa and Ben after Sam died in Swan Song and Castiel never brought Sam and Bobby back.
Dean was bent on his knees where Sam had gone in the box with Lucifer and Michael for about 45 minutes. He couldn't find the strength to stand. He couldn't find a reason. He thought about his promise to Sam. He knew Sam didn't want his brother to look for him. Sam wanted him to live a normal life. But Dean couldn't do that. He could never go back to sanity. He also thought about having a life with Lisa and Ben. But he knew that he couldn't bring his crazy world to them. So what was Dean left to do? Wait for death to finally get to him? Then what? Go to heaven with Ash, maybe see his friends there. But that wasn't enough because Sam wouldn't be with him. What was heaven without your brother?
"Dean." Said a familiar deep voice.
Dean looked up to see Castiel standing in front of him.
"Cas, you're alive? I thought Lucifer killed you."
"He did. I think God brought be back. Good as new." Castiel put two fingers to Dean's forehead and suddenly Dean was healed.
"What are you waiting for Cas, bring Bobby back!" Dean got up and walked toward his friend.
"Dean, I'm afraid I can't do that."
"You can't or you won't Cas!"
"I won't. Bobby is in heaven and he's happy. It's time you lead a normal life."
"Normal? My life is far from normal Cas. Normal people don't deal with this crap. They don't know half the things that are out there in the dark and they don't have their brother in a hole! Bring him back!"
And just like that, Castiel had flown away leaving Dean alone again. If the angel wouldn't bring Dean's family back then Dean would have to find a way to do it himself.
Dean spent the next 4 months travelling the world and looking for answers. He wouldn't sell his soul again because he knew what Bobby would say. He had to find a smarter way. He gathered plenty of books and information but nothing would bring Bobby back without a price.
Dean dealt with his anger through booze and women. He would sometimes go to see Lisa and Ben to make sure they were okay. But mostly he would search and search until the alcohol finally let him sleep. He didn't know where Castiel went but he was to angry to look for him. At this point, Dean was alone. Everyone he knew was either dead or too happy to be brought into Dean's life.
One night, Dean woke up to the sound of heavy wings. He opened his eyes to see Castiel looking outside of the motel window.
"Cas? What are you doing here?" Dean's voice was shaky and tired. These days it always was.
"They died heroes you know." After a moment of silence Castiel went on. "Sam and Bobby. They died saving the world. What more can you ask for. Are you seriously so selfish that you won't let Bobby have the heaven he finally deserves. After all these years of putting up with demons and angels, don't you think Bobby deserves to rest. He's happy. He's with Jo, Ellen and Ash. They found each other. They're peaceful and now it's your turn to find peace Dean. Stop looking."
"And what about Sammy? The poor guy sacrificed himself for the entire world. He saved everybody! And what's his reward? Being stuck in a box with the Devil and an archangel! How is the at all fair? How is any of this fair?" Dean sat up on his bed. "He never even got to live the normal life he wanted. One way or another he was going to get pulled into this crap hole. Whether it was dad or me or Azazel or the angles. He never got the life he wanted."
"Deep down Sam always knew this life would catch up to him. It may not be fair but this is the price of free will Dean. Sam chose his destiny and he saved the world. If all this angel stuff would have never happened, I would have never rescued you from perdition. Bobby would have died years ago and Sam? Sam would have been just as angry as you are now. He would have died an angry old drunk. Would you want that for him?"
"No, of course not."
"Then you know that Sam wouldn't want this for you. Move on Dean. It's for the best."
"Kill me." Dean said as he stood up.
"What did you say?"
"You heard me. Kill me know or I'll do it myself. Like you said: if it weren't for this angel crap I would have been dead years ago. There's nothing left for me here Cas. Please, kill me."
"You spineless insignificant monkey! Have you forgotten what you told to Sam years ago. You told him that this was the family business. You were prepared to save as many people as possible. What changed from then and know, Dean? Because people are still dying and you're sitting here saying that you're useless. The Dean I knew would have never given up like you are now. "
"Don't you think I've given enough to this world? Don't you think I sacrificed enough?"
"Perhaps. But I also think that this might be the only thing you actually know how to do. I know you still think about when all you and Sam had to do was hunt monsters and save a couple people. You still think about how good that felt. And now? Now you think that you can't save anyone? You didn't lose the ability to help people Dean. You lost your reason. But I'm giving it back to you. Hunting abominations and saving people is the only thing that can get you through the day."
"Cas, they're gone. They're not coming back and I know that now. But how am I supposed to go on! How am I supposed to live like this. I have no one by my side. NO ONE!" Castiel can see the tears in Dean's eyes and hear the fast beat of his heart and he knows there's one thing left to say.
"You have me. I'm your family now and we have to hold on to each other. We can hunt together. It will be easier to have me by your side."
"What, like an angel on my shoulder?"
"Yes, exactly like an angel on your shoulder. You won't have to be alone anymore Dean."
Dean can already start to imagine what his life with Castiel will be like. He absent-mindedly starts to smile.
"Thanks Cas."