Harry attempted to think back to the Black family tree on the wall of Grimauld Place, to remember anyone named Dorea, but he couldn't. The tree had been so vast, so many people had been erased, it was near impossible to remember its entirety without hours of studying. Harry knew of course that almost all of the pure-blooded families were at some point related to each other, but his own grandmother a Black? Wouldn't Sirius have known? How could Sirius not have told him? All he felt was confusion, his mind consumed by questions.
It is no surprise of course that Potter, as a pure-blood, is related to another prominent pure-blooded family. Dorea Black married Charlus Potter with the blessings of both families and Dorea kept close contact with her siblings throughout her life. One of these siblings is the grandfather of the infamous Sirius Black, making James and Sirius cousins.
That explained why the Potter's were so willing to take Sirius in when he ran away from home, he was their nephew. But why hadn't anyone told him? Had his mother known? Did she ever suspect the truth? He stopped himself, startled. He was believing this, all he had was Snape's word, over all that he knew of his father. He felt the anger building inside him, and wanted to tear up the roll of parchment in front of him, but he had to know more. Harry began to unroll more of the parchment when he heard a knock on the door. Frantically he rolled up the parchment and hid all of the rolls in a desk drawer. "Um, yeah, come in."
Hermione tentatively opened the door sticking her head in. "Harry, there you are, we've been looking for you everywhere." She stepped into the office, giving him a quizzical look, and Harry knew she was going to want to know if he was okay, why he was up here. He wasn't entirely sure to the answers himself.
"Yeah sorry, came up here to clear my head a bit, guess I lost track of time. Did you need something?"
Hermione nodded, "Mr. Weasley had a bit of a fall while clearing some rubble, he's going to be okay, just needs a few potions, but Mrs. Weasley wanted to know if you could help them with the rubble, I would but I'm still so busy making potions."
"Of course, I'll be right down."
She looked at Harry oddly, as if she suspected something was wrong, that there was something he wasn't telling her, but she nodded and turned, walking back down the spiral staircase. Harry pulled the rolls of parchment back out of the drawer he had hastily shoved them in and looked at them, wondering what to do with them. Part of him told him to destroy them, throw them into a fire. He knew he couldn't. As much as he hated it, he was beginning to believe Snape. Finally he placed the parchments in a cabinet behind some knick knacks, and went down to assist the others clearing rubble.
When he and the others finished for the day nearly three hours later, he knew that he should go up to bed in what was left of the Gryffindor dormitory, but he found himself drawn back to Dumbledore's office. The whole time he had been helping the others; his mind had been at the top of that staircase, trying to find a way to get back to those rolls of parchment, to know more about his father. Once he was finally able to get away he had to consciously stop himself from running back to Dumbledore's office. When he finally reached the office and opened the cabinet to find the parchments untouched, an inexplicable sense of relief flushed him.
Removing them from their hiding place he sat in Dumbledore's chair, unrolling the first parchment and continuing to read.
Being a prominent pure-blooded family, the Black's were one of the first approached by Voldemort in his early stages of power. I do not know when this occurred, only that it was some time before James' third year at Hogwarts. It was during the third year when several of the other Slytherin boys began whispering of a powerful dark wizard. We knew very little, most of it exaggerated, but even then some people stood out as darker than the others, more eager to gain power. Being only third years, we had not yet acquired the audacity to research dark magic, but even then the sense of adventure was almost palpable. I did not tell Lily of this, afraid that she would disapprove. I did not yet know of Voldemort's view of muggle-borns, though I suspect that some of the others did, I must admit, with the intensity of my curiosity I do not know if it would have made me stop. It is not that I have any aversion to muggle-borns, as proved by my intense love for Lily, but simply my thirst for power. I suppose Potter had some part of this, I wished nothing more than to see him destroyed.
As my interest in the dark arts deepened I began to not only research, but to brew potions and cast spells and curses. At first it was simple things, but as my third and fourth year progressed, so did my skills. Lily began to suspect, and I knew she would not understand that at some level, I was doing this for her. James' attention towards Lily had only intensified; I had become afraid for her safety. Though he had never hurt anyone other than me, I knew what he was capable of, and was terrified that he would snap if she continued to refuse him.
This was the end of the first parchment, and as he reached the last line, he could only wonder, if maybe Snape was right.
A/N: for those of you that don't believe me on the Black/Potter family connection go to .com and go to the families section, if you click on Black you can see the whole Black family tree and see that I didn't just pull this out of thin air. I do not own that site or have any part in it, and give full credit to its proper owners.