The shock of the kickback reverberated up the length of Dean’s arm, traveling quickly through muscles and sinew so used to firing weapons that it shouldn’t have made any difference at all. But he dropped the gun to the ground anyway, fingers numb - just like the rest of him. He couldn’t think - could only stare at the body on the floor.
Sam.
Two minutes ago everything had been fine. Sure, Sam’d been acting weird the last couple weeks, but when wasn’t he? And then it had all changed. His brother’s eyes had gone yellow - that same, terrifying yellow he’d seen in their dad’s that night back at the cabin. Sam’s eyes had gone yellow and… Dean had just known. He’d known it was over. He’d failed.
I couldn’t save him.
Not this time. Those yellow eyes had glinted at him and it wasn’t the demon - it was Sammy looking back at him, it was Sammy… but it wasn’t, at the same time. He’d become something he wasn’t and the promise Dean had made echoed through his mind -
“You have to watch out for me - alright - and if I ever turn into something that I’m not, you have to kill me.”
And then the Colt was just there. It was in his hand, cold and heavy - real. Too real - but he’d raised it, not questioning where it had come from or how he’d gotten it, simply knowing what he needed to do. One bullet left. Just the one - and he didn’t miss.
Straight through the heart.
The voice in his mind telling him that he had a sick sense of humor and right then was a really freaking bad time for his poetic side to come out wasn’t really Sam’s, though it sounded like it. It wasn’t real - nothing but his brother’s body and the blood pooling on the floor, congealing, was real.
He fell to his knees. Reaching out, he touched the hole in Sammy’s chest, fingertips coming away bloody, and it hit him. He was completely alone. He’d managed to get his dad killed and now… now he’d taken care of his brother, too. Everyone he cared about was dead. His family was gone. It was his fault. He’d failed - completely.
For the first time in his life, he closed his eyes and couldn’t keep the tears from rolling down his cheeks.