When she came into the common room the following morning, she found Harry already up and waiting for her impatiently.

"There you are!" he said, as if she'd been sleeping until noon. "Let's get breakfast and then I have to tell you something."

She raised her eyebrows, but she allowed him to drag her to the Great Hall. He didn't explain anything until they'd eaten and had retreated to the Couch Room.

"Alright, spill. What's got your knickers in a twist?"

"Well, I couldn't wait last night to test out my new cloak," he answered.

Donna laughed. "Of course you couldn't."

He waved that away, too impatient to reply. "I nearly got caught by Filch and Snape, and then I stumbled into a room where there was this large mirror, and Donna," he gripped her hand in his excitement, "I saw my family! Not just my mum and dad, but a whole family, with grandparents and uncles and aunts and everything!"

Donna's heart broke all over again at the sheer longing in the boy's voice.

"Harry, you're getting a hug now, just so you know." That done, leaving Harry a tiny bit confused what brought that on, she asked: "Mind if I come with?"

Harry nodded earnestly. "I'm going back tonight. I really want you to see them too, I want to show them to everyone."

Donna wasn't at all sure she'd actually see his family, but she was interested in this magic mirror all the same.

"Any reason why you want to go tonight?"

"I want to see them again, of course!"

"Yes, I get that, but I mean... it's still christmas hols, our homework is done until the new term starts, and we have a whole day ahead of us. Why not go now?"

Harry stared at her, as if that possibility had not even occurred to him. "Oh! Uhm... what if we get caught?"

"Doing what? If they didn't want us visiting the magic mirror, they should've hidden it better. If we wait until tonight, we'll be breaking curfew, so more chances of getting caught. If travelling with the Doctor has taught me one thing, it's that you generally get further if you act like you have every right to be where you are, which in this case is easier to pull off during the day."

Harry laughed a bit ruefully while flattening his hair, a nervous habit he'd picked up somewhere. "I guess. It seems less adventurous than sneaking out of the dorms after curfew, though."

Donna shrugged. " I said it before and I'll say it again – being brave does not mean we have to be stupid too."

They ended up visiting the magic mirror after lunch that day. Harry needed a while to remember his route the previous night, what with everything looking different in daylight, but with some encouragement from Donna – not to mention experience with exploring – he recognised a suit of armour, and from there he easily found the right door. He pushed it open and ran to the tall mirror standing in the middle of the deserted classroom, gazing into it reverently. Donna followed a bit more warily.

"See?" Harry whispered. Donna came up behind the boy and looked over his shoulder.

"I can only see the two of us," she said.

Harry moved away from the centre spot in front of the mirror. "Stand over here! Can you see them now? Or maybe you can see your own family?"

When Donna took up the vacated spot, she didn't know what to expect. Would she see Harry's family, as unlikely as that seemed? Her own mother Sylvia and Grampa Wilf?

In the end, it was an entirely different scene that unfolded in front of her eyes. She could see herself – her grown-up self. She knew instinctively that this was a reality where the Doctor had never been forced to wipe her memory, where she was the DoctorDonna with a brain that could keep up with the Human-Time Lord metacrisis. Behind her stood a tall blue box with its door invitingly open, showing the bigger dimension inside. Leaning against the box was a man with messy hair, a brown pinstripe suit and a long coat, grinning manically and every now and then wiggling his fingers in a kind of wave.

"Oh."

That was all she could say, before gently placing her hand on the mirror glass, over the open TARDIS door. God, she missed that daft alien with his (daft) lovely ship. She closed her eyes, willing away the tears – not entirely successfully.

"Donna?" Harry asked, sounding concerned about her reaction. "What do you see?"

She bowed her head and let go of the mirror, taking a deliberate step back. Then another. She turned away and wiped the tears from her face with both her hands, before looking at Harry with a serious face. "An impossibility. A dream. That is a dangerous mirror, Harry. Please, please be careful."

The boy looked taken aback at her vehemence, but even as they left he cast one longing look over his shoulder. She wasn't sure how successful he'd be in staying away.

In the end, he'd been going back in the evenings, and she had to watch his listless expression with worry during the day, trying to convince him to eat. On the third night after discovering the mirror, Gandalf revealed himself. He convinced Harry to stop obsessing over the mirror, so that was something. Perhaps she should have tried harder, but she couldn't begrudge him the small glimpse of a family long dead, not when he'd had nothing to remember them by before now.

At least he acted a bit more lively and interested after his talk with Gand- Dumbledore, even if he looked a little bit wistful at times.

"Harry," she asked the following day, when she noticed him looking off into the distance again, "Do you have any pictures of your parents?"

There were only a couple of days left before the end of the holidays and the return of their friends, but she wanted to help him now, not later. Harry looked sad. "No, nothing. I don't think aunt Petunia kept any of them, or if she did she never showed me."

"Ok, I thought you mentioned that. But people are always comparing you to your dad, right?"

"Yeah. But with my mum's eyes."

"Right. Correct me if I'm wrong, but doesn't that imply to you that they actually knew your parents?"

"Well yeah, of course, but nobody's ever told me anything about them, other than what you said."

"Do they know how little you know about them? Have you tried asking them for stories?"

Harry stilled, his eyes going just a bit wider. "You mean... go up to them and ask?"

Donna chuckled. "Yes, that is exactly what I mean."

"That's an option?"

"Sure, why not? What's the worst that could happen? There's loads of teachers old enough that they must have taught them."

"But what if they don't want to tell me?"

Donna shrugged. "Then they'll tell you so, and you'll know. At least you will have tried."

***DNMCY1***

And that was how they found themselves in professor McGonagall's office later that day. The stern witch regarded them over the rim of her spectacles.

"Mister Potter, miss Noble. To what do I owe this visit, and during the school holidays no less?"

Donna nudged her friend. "Harry has a question," she volunteered when the boy didn't immediately speak.

The professor turned to give him her full attention. "Mister Potter?"

Harry fidgeted under her gaze. "Well, uhm. I was... was wondering, uh..."

"Gryffindor courage, Harry. Spit it out," Donna whispered.

A flick of the eyes and a slight purse of the lips – as if she was forcibly restraining herself from smirking – were the only signs McGonagall gave that she'd heard the words at all.

Harry nodded and took a deep breath.

"I was wondering if you knew my parents."

This time she raised her eyebrows and sat back in her chair, crossing her hands in front of her and regarding the boy.

"Might I enquire where this question came from?"

Harry seemed to shrink a little, but when Donna touched his arm he rallied.

"Well, I don't really know anything about them, you see, and Donna thought some of the teachers might have been here when they went to school, and since you're our Head of House we came to you first."

All this was said quite rapidly, and when he was done he tensed up, as if anticipating rejection.

Professor McGonagall's eyes softened marginally. "I see. Please take a seat, both of you. You said you don't know anything about them? I should think your aunt would be able to tell you about your mother, at least, if not your father. Did she not?"

Harry shook his head and shrugged. "She told me my parents were useless and died in a car crash while driving drunk. That's about it. Oh, and she was jealous of mum being a witch, but she didn't tell me that so much as she ranted it at me when Hagrid gave me my letter."

Again the professor pursed her lips, this time in disapproval. "Well, let's see if we can rectify the situation, hmm? I think this calls for tea and biscuits."

And that was the way they spent their last couple of days of the holidays: seeking out anyone who might have taught or known Harry's parents, and begging them for stories.

One thing emerged from all of these stories clear as day. His mum had a very close friend during her time at Hogwarts, up until fifth year, at which point something happened to drive them apart. And that friend just happened to be their Potions teacher.

"But he hates me!" Harry said, when they were discussing the possibility of talking to someone who had been so close to his mum. Donna nodded. There was no point in denying it, when it was so obvious.

"It's your decision whether to reach out to him or not, Harry. I understand either decision. On the one hand, he was quite close to your mum, but on the other he has it out for you, for whatever reason."

"Maybe I could wait a bit?" Harry asked hopefully. "See if he ever stops hating me?"

"Sure, you could, just don't hold your breath. Whatever the reason for his hatred, it probably originated during that time. I mean, prior to that first lesson in September, I don't think you ever talked with him?"

Harry shook his head.

"So it can't be about something you did personally. It wouldn't surprise me if Snape is having difficulties distinguishing between you and your dad. They didn't get along, according to... well, everyone. I'm sure there's some psychological name for that. Some fancy name for 'refusing to grow the hell up', no doubt."

Harry let out a tiny laugh, which she counted as a win.

"Ok, but then we've talked to everyone else, right?"

"I think so, and in any case you have quite a lot more stories now than you did before. As far as I can see there is one more thing you could do, if you wanted."

"What's that?"

"You could write that Lupin bloke that kept getting mentioned. He was as close to your dad as Snape was to your mum, and he's not threatening to turn you into potions ingredients every time you breathe."

"Do you really think he'll want to hear from me, though? It's not like he ever came to check up on me in the past ten years."

Donna shrugged. "Only one way to find out. If he replies, you can always ask why he never came. He might have had a good reason."

"Yeah, ok. I'll think about it."