"The darkest mark is the one made in the heart."

The headmistress has never experienced such a storm in her whole life in Hogwarts. She took it as a bad omen. She stared out the window, hoping she had not found the letter that now laid open on her desk. She couldn't believe it. All this time, Dumbledore had been keeping something this important from her.

"She ain't an infant is she?"

Hagrid's voice had called her back to the present. She had almost forgotten she had called for him. She had almost forgotten what the contents of the letter had asked her to do.

"No," she answered, trying to keep her composure. "She's about Harry's age I believe." She let the words hang in the air for a short while before walking over to the letter. It was faded. Like it had been kept in a drawer for too long. Her eyes fell on the picture attached to it. A little girl was standing in the picture, looking directly at the camera. She had a smile on her face, but her eyes held so much sadness.

There were at least 20 letters. All sent from the same address. Dorset in England. One letter per year, except when the girl had turned 14. 3 letters were sent that day.

In one picture, the girl was smiling at something. A butterfly paper she had managed to lift from her hand and make its wings flap. The letter simply wrote:

She can use Magic, Albus.

The next was a picture of the girl sitting by the window. As if waiting for something. In the letter, the sender wrote:

She does not remember her parents but knows they have been killed. When are you visiting? You know how sad she gets when she does not see you. You are the only one who connects her to the magical world. The only one who makes her feel normal. Albus, what do I do? How can I help her?

The last one had no picture. Just a letter in which, upon closer inspection, seemed to have been written in quite a hurry.

Albus. We had to move. The nightmares are back. She keeps screaming. The sounds frighten me, Albus. When are you coming? She keeps calling for you. She is so afraid. How do I help her?

After that, the letters came once a year. The picture attached to them differed as the girl grew older. There was no longer any mention of nightmares, or her parents, or Albus. It was as if the sender had given up trying to call Albus back for a visit. Still, the letters came. McGonagall had thought the narrative had also changed and thought perhaps the little girl had been writing the letters, not anymore the old sender. The thought made her shiver. The original sender had sent the last letter, the headmistress could tell from the familiar scrawl. It was simple and consisted of only three words.

She remembers Malfoy.

Which was why the headmistress had called for Hagrid. She needed to know about this girl and the mysterious writer and what the Malfoys had to do with it. Why had Albus ignored all this? How is he connected to the girl? There were so many questions she had to know the answers to and everything- everything was pointing to the girl.

"I would just want you to take a look," she spoke slowly, thinking of her words carefully. "I want to know where this girl is living. Who is with her? Does she know of Hogwarts? Is she blending with muggles-"

"Aye, ye' want t'know if she's dangerous?"

"Not exactly, no, I want to know who she is and why Albus kept a connection with her but did not reply," she explained. She didn't know how to explain what she had wanted Hagrid to do. She didn't even know if the girl still lived in Dorset or if she had been aware of the wizarding war.

One thing she was sure of, though, was that she was someone important. Important enough for Dumbledore to keep secret.

"I do not believe she is dangerous," she continues. "I just think she is someone important and I want to know why, perhaps her guardian would provide us with answers but I cannot leave the school yet. I cannot leave the students."

Hagrid nodded. He understood. He waited to be dismissed but noticed that the headmistress had begun staring out the window again, lost in thought. He decided to leave without saying anything.

Headmistress McGonagall was holding on to the recent photo of the girl. She stared at it as she walked back to the window. The wind outside sounded almost desperate to break in through the window.

The girl stared back at her from the photo. She was smiling, a flower in her hand. That was not what McGonagall found odd. Neither were the color of her eyes, which were different. One was a cerulean blue, the other bright green.

No...It was the scar on her wrist.

The mark of an unbreakable vow.