Prologue

Harry walked down the stairs of Grimmauld Place in search of Ron and Hermione, hoping they had an idea as to who the girl was he had just found a photo of, in fact, he had two photos of her.

One he had found in Regulus Black's room after it was discovered that he was the one who originally removed the locket from the cave in an attempt to help bring down Voldemort but he didn't say anything, assuming it was some girl that Regulus must have cared for.

It wasn't until he was in Sirius' room, looking for anything to help link him to his late godfather, aside from this horrid house they were currently hiding out, in that he found another photo of her.

He had to admit that she was beautiful, the old photo gave that much away but he was still curious as to who the girl was that both brothers seemed to care for and considering Harry had the impression from Sirius that the brothers didn't care for each other, he was highly curious.

"Take a look at this," Harry spoke as he entered the kitchen, walking over and placing the two photos in front of his best friends.

"So it was a girlfriend of Sirius' back in the day," Hermione spoke, dismissing the topic but Harry shook his head.

"I don't think so. I found this one in Sirius' room and this one in Regulus' room. Care to explain that one?" Harry spoke, pointing to the different photos.

It was then that the two of them finally took a good look at the photos in front of them.

"She's fit," Ron commented, earning a slap on the back of his head from Hermione while Harry let out a small chuckle at the action.

"I don't know what to tell you, Harry. Maybe once this is all done with or we see Lupin again anytime soon we can ask him, but for now, Umbridge and the locket are our concerns," Hermione spoke, moving the photo back across the table and allowing her to look back at the books she piled around her at the table.

Harry let the topic of the mysterious girl disappear as they did have more pressing topics at hand to worry about.

But it was when he walked past the drawing room a few days later that he caught sight of Hermione in there, positioned in an armchair with a book resting on her lap. She wasn't looking at her book though, she was looking at the wall and when Harry entered he noticed she was looking at the Black Family Tapestry.

"Everything alright?" Harry questioned, walking over and standing beside her, looking at the tapestry as if he could find what she had.

"It's just that photo you showed us the other day. I thought maybe it was a family member, we heard Sirius speak fondly of Tonk's mother but there is something bothering me," Hermione responded.

"What's that?"

"Well look at the siblings, even where the scorch marks lay. All children that come from parents bearing the surname Black have three children, why was it that Sirius' parents only had two?" Hermione pointed out and Harry finally saw what Hermione was seeing.

He walked closer to the tapestry, looking closing at it and he finally saw the faint gold line and he followed it with his fingers but he frowned when he noticed the part of the tapestry had been destroyed, either eaten by doxies or ripped off at one point.

"There was a third sibling, you see the gold line but the part of the tapestry that would hold the picture of the sibling is gone," Harry responded and it wasn't long until Hermione was standing beside him.

"So Sirius had a sister that could explain why both he and Regulus had a photo of her in their rooms," Hermione responded.

Harry couldn't help but wonder what happened to her, no one made mention of her and in Sirius' will he was given everything with again, no mention of her.

But it was when Harry thought back to the last summer he spent with Sirius, there was one room that they were denied access. Sirius claimed that his mother must have charmed the door to stay locked for whatever reason but now he wondered if Sirius had done it, that maybe it was his sister's room.

But unlike with Sirius and Regulus' rooms, there was nothing on the door indicating who the room belonged too.

It wasn't until Harry, Hermione and Ron were at Shell Cottage after escaping from Malfoy Manor and Remus had shown up that he was able to finally question someone who could potentially know who this mysterious girl was.

"Did Sirius have another sibling aside from Regulus?" Harry questioned as he took a seat beside Lupin at the small table.

Lupin's whole body froze, his cup half-way to his mouth to take a sip.

"Why would you ask such a thing?" Lupin questioned.

"I found a photo of a girl in both Sirius and Regulus' rooms. When looking at the tapestry I noticed a gold line linking to what would be another sibling but there was no picture, that part of the tapestry having been damaged," Harry explained.

Lupin placed his cup down on the table and pinched the bridge of his nose. "Yes, Sirius had a younger sister, one who was two years younger than us at Hogwarts. She was killed in the summer of 1980, mere weeks after her own graduation from Hogwarts."

Harry fell silent, staring at Lupin and the pain that evident on the older wizard's face. It was the same pain when he had asked him and Sirius about his own parents.

Lupin obviously cared for Sirius' sister.

"She was the only thing that Regulus and Sirius could agree on, her name was Capella Walburga Black," Lupin added in before he stood up and left the table, leaving Harry alone.

.oOo.

A/N: Thank you for giving this a read, I can't promise when the next chapter will be posted as I just had to get the idea out there and see how it will be taken.