The Girl Who Survived

Everyone's heard of the Boy Who Lived. They all worshipped him, and why wouldn't they? After all, he did survive the killing curse. Every single person knew that You Know Who had gone for good, and even if he were to return, (which was highly impossible, in the opinion of the public) the Boy Who Lived would definitely defeat him.
However, what they didn't know, was that he wouldn't defeat You Know Who alone. Someone, who holds power one couldn't even dream of, would fight alongside Harry Potter. A girl, who'd sacrificed everything.

Cassieopeia Lyra Lupin-Black.

She doesn't know. She doesn't know her real name, her true parents, her real HOME. She doesn't know. She only knew what was told to her, which was all lies.

'Dumbledore, are you in your right mind?'
'I have never been in it, what makes you think I would be now? I simply am doing what's for the best.'
'For the best? Albus Dumbledore, putting the girl in an orphanage, then handing her over to bloody death eaters! That is not "for the best".'
'Minerva, you know the danger once Voldemort knows of her existence. For now, she is Cassieopeia Lyra Smith. A muggleborn, who was adopted by these people for reasons she knows not. She will know, I promise, but now is not the time. All will be clear to her when the time comes. You need to believe me Minerva.'

Said woman sighed and brought up her hand to fix her spectacles.

'Albus, I won't say anything to this, but remember, tomorrow if that girl goes against you and joins You Know Who, it's all going to be on you.'
'That won't happen Minerva, I assure you.'
'Yes and when have any of your assurances ever been reassuring?'
'That depends on you whether you believe me or not. That girl, she holds power which even I won't be able to handle, and that is saying something. Believe me, Minerva. She will be Voldemort's doom.'

And she was.

Credits to @prxttyslut for the book cover

DISCLAIMER: I do not own Harry Potter. I only own Cassie and her storyline.