"She's half angel." Cas stated.
There was a deafening silence as both Sam and Dean stood slack jawed. They weren't the only ones. You also found you were staring disbelieving at the angel.
"H..how?" Dean finally broke the silence.
Cas stepped up to you and placed a hand on your head for a moment.
"Your father was Michael's vessel for a while before you were born Dean. He was again when he met Y/N's mother. Michael must have erased your fathers memory of it. Michael has never sired any children before, you are the first." Cas explained seriously.
"So why would demons want her specifically? There are other half angels out there." Sam asked.
"She's the most powerful half angel of them all and also your sister. They probably want to use her against you to make you stop hunting their kind. Either that or they think they can turn her, she would be a powerful asset to them if they did. If they wanted her dead she would be already."
"Ok so how do they know who she is or even what she is? Is she marked or something?" Dean asked quickly.
"I'm not sure. Only angels can tell for certain and even then we need to be close to sense it. Demons need to be very close to sense anything. I think someone may have tipped them off."
You began to feel sick and the longer to stood listening to what Cas was saying the worse you felt. You went outside for some fresh air and also to try and make sense of what he had told you. Among everything else you felt you began to have a growing fear that your brothers would hunt you. In the last few days you had started forming a bond with them both and you feared them learning you were different would make them want to hunt you like all the other monsters they hunted.
"Hey, you ok?" Sam appeared silently behind you making you jump.
"Yeah, just needed some air."
"You don't have to worry you know, we won't let anything happen to you." He squeezed your shoulder reassuringly.
"It's not just that." You replied without even thinking.
"Then what? You think we're scared of what you are?"
You turned to face him and nodded grimly.
Sam smiled sympathetically. "Well we're not. You're still our little sister. Besides Cas is an angel we've known for a long time and he's pretty cool. We'll figure this out, we always do."
You gave a feeble attempt of a smile.
Sam didn't buy it and enveloped you into a big warm hug. He was a lot taller than you and your head rested against his warm chest. You felt safe in his arms. He released you and looked straight into your eyes.
"Come on, i'll make us a hot chocolate."
You followed him back inside where Dean and Cas were still talking. They stopped once they saw you and Cas looked straight at you making you feel a little awkward. Dean came over to you.
"You ok?" He looked at you with concern.
"Yeah, just a lot to take in these past few days."
"Well I'd say your handling it well considering. We'll make a hunter out of you yet." He ruffled your hair playfully.
You couldn't help but smile. Dean had at first been rude and rather off putting when you first met him but the last few days had changed that.
"So anything else I should know?" You turned to Cas.
"That is all I know for now." He replied.
"Do you hunt?" You asked trying to ease the awkwardness.
"Sometimes. I'm not as good as your brothers though."
"Don't put yourself down Cas, your a pretty good hunter." Sam came in carrying two mugs of hot chocolate he handed one to you.
"Thanks." You replied as you took the offered mug.
All four of you laughed and joked until retiring to bed for the night. Cas offered to watch over as the three of you slept.
/\/\/\/\/\/\/\/\/\/\/\
"Y/N. Y/N." Dean screamed as a demon stabbed him.
You tried to run to help him but couldn't seem to move. Another demon was attacking Sam. You couldn't move to either of them and it frustrated you. The demon attacking Dean turned to you and laughed a blood curdling laugh before running the knife it had straight through Deans heart. The other demon followed suite and ran its knife into Sams heart. You screamed.
/\/\/\/\/\/\/\/\/\/\/\
"Y/N, hey."
You woke with a start a looked at the person who woke you, trying to focus. After blinking a couple of times you realised it was Cas. He stood over you looking very worried.
"Are you alright?" His voice was deep but full of concern.
You looked over at your sleeping brothers at the other end of the room.
"I had a nightmare." You replied barely above a whisper so as not to disturb them.
Cas tilted is head slightly.
"If I stay with them they'll be killed."
"They can protect you and themselves, i've seen them hunt far worse things than demons. Your brothers will be fine and they can and will protect you." Cas reassured.
"The demon that's after me will kill anyone who tries to stop him, he almost killed Sam that night at the hotel. I can't watch them die. I've lost enough people I care about."
Cas sat down beside you on the makeshift bed.
"You won't lose them. Demons like making people fear them and are evil but Sam and Dean have killed many of them. It's only a matter of time before they kill the one looking for you. You need to be brave and strong."
You nodded your head reluctantly. Cas placed a hand on your shoulder reassuringly before returning to his guarding spot near the front window.
You lay back down unconvinced by Cas' words, you felt the only way your brothers would be safe was if you left.
Early the next morning as the guys were packing up you saw an opportunity to slip away and took it. None of them had noticed you leave and you were confident you could make it on your own.
You moved quickly through the woods until the little house was completely out of view. You felt bad for leaving without saying goodbye but knew they would have only tried to stop you.