The boys just stared, dumbfounded, at the Angel. A sister? How was this remotely possible? Dean had took a double take before being the first to speak.

"Uh, sorry but, what? How is this even possible, Cas? I'm sorry to break it to you, but our parents are dead, and if they did have another child, don't you think we'd know?"

Cas looked at Dean seriously,

"I can assure you, this is no joke, she's-"

"Then explain!"

The young girl stared at her so called brothers, a look of recognition on her face, Sam figured she must know who they are, but he had no idea how, though.

"I don't think you'll want to hear this" Said Cas.

"I don't care, we need to know, NOW!"

"Fine" Cas sat next to Dean, he looked almost as worn out as Sam and Dean

"She IS your sister, but she was never born. Only a short while after Sam was born, your parents conceived a third child, they didn't know at the time, it was too early to know she was pregnant. But Azazel murdered your mother on the night Sam turned six months, as you know. But what you may not know is before setting fire to the house, Azazel realised Mary Winchester was pregnant, and sliced open her stomach, killing her unborn child before she followed shortly after…"

The brothers couldn't believe what they were hearing, but before they could say anything, Cas piped up again.

"I'm sorry, I know this is a lot to process, I shouldn't have told you."

There was a look of the upmost terror on Sam's face.

"Wha-wait, the night Jess died, she..her stomach was..no.."

Cas gave a sad and concerned look towards his friend, Sam was about to break down, finding out his sibling was murdered before his mother even knew she was going to have another child, but the thought of also loosing a child along with the person he loved most, was just too much for him to take in one go. Small tears began to streak down his face.

Dean could only stare at the girl, a small wave of fear washing over him. Looking after Sammy all these years was hard enough, and he'd mostly failed, but another sibling? Sam had been killed before, so had he, they were so much more lucky than they should be, still alive and kicking like this, but she might not be.

"If it's ok, we should be going." Cas said

"No. She's staying with us, Cas if she's our sister, she has every right to- hang on a minute, if she was supposed to be born only a year or so after Sam, why does she look, what fifteen?! She's supposed to be over double the age she looks!" Dean said

" It was the book that brought her back, In it contains a spell for bringing back the dead, but it comes at a price. Angel blood…you need Angel blood for the spell to work, by the looks of it, those demons that brought her back were only able to obtain half the blood they needed, because they couldn't kill any other Angels, or they could've had a deadline to bring her here."

And for the first time, the girl spoke,

"So, you guys are Sam and Dean, right?"

Sam looked at her sympathetically

"Yeah, we are."

"I don't have any memories of you two."

Sam changed his look to a more confused one.

"Cas? Got any explanation?"

"According to the garrison, she has a memory of her whole life, a life that didn't actually exist. A whole timeline of different events to your lives inside her head."

Sam turned to her,

"I'm sorry, we don't even know your name, it's really rude of us not to ask, so, what is your name exactly?"

She looked a tiny bit suspicious, she also seemed to look at Cas for reassurance, as if she needed permission, he did nod, she breathed out.

"My names Arra, Arra Wicnhester."