The first month at Hogwarts went by in a blur. She hung out with Ginny, and a fair bit with Luna, too. Hermione had become too busy with her load of schoolwork to speak to anyone. Professor Snape kept giving her dirty looks, and Professor Lupin kept giving her strange looks. Then one day, at the beginning of October, his look had gone from strange to... well, she couldn't entirely describe it. Almost horrified. He asked to see her after class.

"Did you find out who I look like, then?"

"There was never any question who you looked like, Ariana, I had just thought it to be coincidence. When were you born?"

"August 31, 1981."

"And who are your parents?"

She shook her head. "I have no idea. They died sometime in October."

He went very pale. "No idea?"

"No. Do you have a guess? Because I've been trying to figure it out since I came here last year. I keep getting dirty looks from Professor Snape-"

"Yes, I imagine you would. So, your parents died in October of 1981?" His voice had gone quiet.

"Yeah. The same month as Harry's parents. You knew them, didn't you? At least his father."

Professor Lupin looked caught off guard. "How would you know that?"

"You said your friend was Head Boy, and Harry said his father was."

"Right... you haven't said anything to Harry, have you?"

"No."

"Good."

"But, professor..." She tried to think of a way to voice the question that was burning in her mind. "Do you think you know who my parents were?"

"No, Ariana." He took a deep breath. "I am fairly certain I know who your parents were."

"Who?"

He shook his head. "It's not my place to say. If it's a secret, it's a secret for a reason."

"They're my parents."

He did not reply, but Ariana felt her mind racing. He had known Harry's parents, and he had known hers, and she did look like Harry's mother... No, she was being ridiculous again. Harry didn't have a sister, there had been no other child in that house that night. Yet all the evidence seemed to suggest it. She shouldn't say anything.

"Well, professor. If that's all, I'll be going."

"Yes." His face was now nearly as white as snow. "That's all."

By the time Halloween rolled around, Ariana really thought there was credibility to the theory that she could somehow be Harry Potter's sister. The idea was insane, she knew, and maybe borne of desperation, but there was evidence. The only problem was, who could she tell? Everyone would think she was crazy. Even Ginny. Then she thought about how Ginny had told her last year when she was opening the Chamber of Secrets. She had trusted Ariana with something very important; surely Ariana could trust her?

"Hey, Ginny," she said one evening, trying to sound casual.

"Yeah?"

"I was just thinking, about something weird."

"Hmm?"

"Last year Harry showed me some pictures of his parents."

"Yeah?"

"Yeah. The odd thing was, I looked kind of like his mother."

"That is odd."

"Yeah... And Lupin was friends with his father, and recognized me."

"Are you suggesting what I think you're suggesting?"

"I don't know. Do you think it's possible?"

"That you're secretly Harry's sister? I mean, I guess anything is possible. Wouldn't exactly say it's likely."

Ariana nodded. "Right. Of course. Forget I said anything."

But that night at the Halloween feast, Ariana found herself sitting right next to Harry, and all through the meal could not drive the possibility from her mind. Afterwards, they went back up to their dormitory, and only then did Ariana forget about her musings. For there was the Fat Lady's portrait... but the Fat Lady was not present. And the portrait was slashed open.

What followed was complete chaos as the teachers attempted to search for the Fat Lady. Ariana felt her heart racing. Who would have done such a thing? Who would have slashed her open like that?

When they did find her, what she said did not make things any better. Sirius Black! Sirius Black had tried to get into their dormitory. A dangerous, escaped murderer. And he had been right here, in their castle.

Everyone slept in the Great Hall that night. Ariana was next to Ginny, and whispered quietly, "Why would Sirius Black try to get into the castle? Your father said he wouldn't."

"I have a theory," Ginny whispered back. "And it's not a good one."

"What?" Any theory would be better than the idea that a murderer had just come to a school full of children on a whim.

"Sirius Black was supposed to be a follower of... You-Know-Who."

"Oh."

"He might be here, well..."

"To get revenge on Harry?"

"That's the theory," Ginny said. "Like I said, it's not a good one."

"But don't you think someone from the Ministry would have said something if they knew that Black was going to head towards Hogwarts?"

"Not sure," Ginny replied. "Who knows why the Ministry does anything? Fudge is an incompetent-" She cut herself off when Percy walked by their sleeping bags on his patrol. "The point is, that might be the truth or it might not; we really have no way of knowing."

"Well, great," said Ariana. "So we have no way of knowing whether or not he's coming back?"

"That's the gist of it."

Ginny went to sleep a few minutes later, but Ariana tossed and turned a little bit longer. If, hypothetically, she was related to Harry, and Black was after him... would he be after her, too? She shook her head; as Ginny had said, it was a ridiculous thought anyway.