He wasn't sure what made it happen. He wasn't sure how he even did it. All Sam Winchester knew was that one second he was riding backseat with Lucifer calling the shots in his meat suit and the next… well suddenly he was back in charge.

He had been screaming and raging and trying to stop himself as Dean had died, as he had killed him, but nothing had worked. He still put his foot on his brother's neck, still pressed down until he heard the snap, he still watched the light go out of his beloved brother's eyes. It all felt like it was happening so fast. Suddenly there was another Dean. He fought even harder then; he didn't want to see his brother die twice. He listened as Lucifer stole his voice, spewing poisonous words at the other Dean. He watched as Dean, past Dean, vowed to stop all of this from happening. Sam could feel his heart breaking, his soul was on fire, and he wanted to tell him. He needed to tell him.

But just as he wrestled control away from Lucifer and reached out his hand the other Dean disappeared, and Sam was left alone. He reached into his pocket and pulled out a small metal object; four rings stuck together in a circle. His brother had never known how hopeless it had really been. Lucifer had been in possession of the only thing that could stop him for years; saying yes had been a kindness. Or at least Sam had thought that at the time.

Lucifer fought him for control but Sam needed time to grieve, time to think everything over, and he pushed him back. Dean was supposed to say yes to Michael after Sam said yes to Lucifer. That had been the plan. Sam was supposed to put the apocalypse back on track, but the angels had long since stopped listening. Michael was gone, or didn't care, and instead of fixing things Sam had simply made them worse.

Now Dean was dead. So were Cas and Bobby and Ellen and Jo. He had known his brother's strategy weeks ago; his attempt at a distraction had killed the last remnant of their friends who had survived this long. Sam swallowed hard and Lucifer tried to regain control, more aggressively this time, more desperately. Sam just wanted his moment, one moment without Satan in his head, one moment to grieve his loss with the use of his body. Sam just wanted one second to himself. Past Dean was gone, present Dean was dead, there was no one Sam could tell the secret to Lucifer's defeat to anymore. So why was Satan getting so damn nervous?

Sam looked at the rings in his hand, and he understood.

It wouldn't stop the apocalypse, nothing could do that now, but it would still get him revenge. He looked at Dean, crumpled and motionless on the grass, his neck turned at an unnatural angle. His brother's eyes were glassy and vacant, staring back at him in accusation. But Sam could still avenge him. Sam had spent the last year listening to Lucifer gloat. He had heard every reason why Dean would fail, every scenario of how he would die and leave Sam to rot in his own body. Sam knew how to get his revenge.

The internal fight was raging now, and Sam knew he couldn't keep control much longer. He flung the rings onto the ground and watched as a void opened up in the center of the garden. Without hesitation he leapt towards the center of it, Lucifer regained control a second too late and they toppled down towards the cage. Sam's last coherent thought was an apology to his older brother.