Sam's PoV

We laid Grace down in one of the rooms as Castiel got to work healing her. He said he wouldn't be able to do it all at once because he was low on power after healing us all - that and the injuries I'd given her were particularly bad. Dean grabbed my arm and yanked me out of the room, into the library where he practically threw me into a chair.

"Explain." He demanded, slamming his hand down on the table as he sat opposite me, interrogation style. How could I explain it? He'd just see me as incompetent and once again little Sammy would be cast away from any cases for fear that I'd screw it up just like I had now. "All you had to go was go into the room and say an exorcism. Hell, if Grace can exorcise two demons then you should be able to do it. Instead, we hear her screaming and when we come in she's hurt." Fire burned inside me as I remembered what the demon had said about mum, Jessica and Grace. Once again, I was barely in control of my emotions.

"What do you care anyway? Ever since we met Grace you've been a jerk to her. She was trying to help us and you pushed her away, made me get turned into a vampire." I shouted, as if the demon was now possessing my thoughts and feelings. Clearly they'd upset me more than I'd thought and now I was taking it out on my brother.

"You should be able to handle yourself Sam and clearly, for some reason, you're not thinking straight." Dean leant back in the chair, giving me a judging look. "It has been known for people to remember what happened to them while they were possessed. She trusted you and you stabbed her!" Dean leant towards me once again and kept his voice quiet. "So you either tell me what happened or I'm going to have to bring it all back up with her later - if she makes it out alive." The last sentence caught me off guard and I moved my head down, running my fingers through my hair as I sighed.

"Stop treating me like a kid, Dean. I don't need threats." I said sadly, remembering every piece of what happened as if it happened a minute ago. "You think I don't hate myself for doing it? For letting the demon get to me? I can't even look her in the face man. I know I screwed up." I dropped my head once again, regret filling my body and making it heavy. She had done nothing but good for us and I couldn't even hold my nerve against a demon. What was I going to be like if we did come up against lucifer? Or anyone else for that matter. Dean gestured for me to continue, knowing that speaking about it was the only way for him to understand. I sighed, ready to tell it all. "The demon spoke about Jess, about mum and how she died... they went into such ugly detail and I just lost it. I wanted to hurt that demon, to kill it for what it was doing to us..."

"So you stabbed her in the stomach and the demon sparked out. So what was all the screaming after that?" Dean questioned, still unsure that I was telling him the whole truth - and I knew I wasn't going to. That demon knew about Grace and I being closer than any of the others and they knew that when they spoke about her death, I'd get angry. I couldn't tell Dean that no matter how much I wanted to.

"No, Dean, the demon didn't spark out. That's what was weird. It pushed itself away, brought Grace back for a second and so when I stabbed her, it was actually her. As soon as she passed out, the demon was back. The demon was the one screaming all that stuff, not Grace. And I wasn't even touching her, I'd thrown the knife on the table as soon as I'd realised I'd stabbed her and not the demon." Dean took in everything I said and pulled a few confused faces as he tried to compute it all.

"The demon somehow brought Grace back to take most of the injury from that blade and then acted like her to make you look bad?" There was hesitation in his voice. "Come on Sammy, I've never seen anything like that in all the time we've been doing this."

"We hadn't seen a Wendigo before we hunted it but we still believed the lore." I stated, trying to prove a point. Dean remained silent and I let out a long sigh. "Dean, I'm telling you the truth. Look, I know I screwed up. I shouldn't have let the demon get to me and I've told you what happened. There's nothing else I can do. That demon even said it was a new trick they'd learnt." The silence that followed was deafening once again, until Cass walked in and spoke to us, taking the heat off of me for a second.

"She's healing well so far." Cass said as he took a seat at the table with us, trying to offer me a small smile.

"Alright, lets take a break and get ourselves sorted out. In a couple of hours , after some food, drink or a nap, we can regroup and work out what to do about Kelly." Dean ordered as he stood up, walking towards the kitchen with Castiel. I got up to follow, feeling like some food may make me feel ever so slightly better, but as I rounded the corner, I heard the two of them talking about me.

"So what did he say?" Cass asked. I stayed where I was, hiding around the corner as I listened in.

"The demon angered him, he went to stab it but it brought Grace back and she took most of the hit. Then the demon screamed for help before taking off." Dean said in a tone that didn't give away if he believed me or not.

"That's... unusual." Cass said, unsure too.

"Damn right it's unusual. I've never heard of it. Is there any way we can prove it?" Dean asked carefully. My chest tightened as I heard my brother asking for proof of what I'd said. He didn't believe me. He thought I hurt Grace on purpose.

"That's a lot to make up, Dean, even for you guys who have seen almost everything. I mean I could check her memory but she may not have recollection of that. If that's true though, demons just became a whole lot harder to kill."