AN

On the Saturday of the week following the Troll incident, Donna sat cross-legged on a couch in the Couch Room, with her friends sitting around her in various degrees of anticipation. She had decided that she should start trusting some people, and who better than the friends who had faced down a troll together?

Hermione was practically bouncing in her seat at the thought of secrets to be shared, while Neville and Harry looked calmer, if no less curious. Harry was the first one to break the silence. Surprising, she would have expected Hermione.

"Well? You wanted to tell us something?"

"Steady on there, cowboy, I'm still trying to figure out how to tell my story. Even knowing magic is real, it's a weird story. Also I'm not sure where to start, by telling you my age or my birth year."

Donna paused for a moment, gathering her thoughts. "Alright, so... start at the beginning, I guess. I was born in 1970. Yes, Hermione, I know that makes my age closer to 21 than 11, let me tell my story.

"Like I said, 1970. When I turned 11 years old... absolutely nothing happened. Well, I guess I had a birthday party, but that was par for the course and so long ago that I hardly even remember it, so that doesn't count. All the stories I've been telling involving my mum are from that time.

"I went to school, then to uni, and when I graduated I did some temping, ending up at a security firm as a secretary. I met a man there, a wonderful man – well, I thought he was wonderful at the time. We were going to get married. In fact I got all the way to walking down the aisle, when the magic entered my life, if not quite in the same way as yours. One moment I'm looking at my soon-to-be husband, the next I'm standing in the oddest-looking room you can imagine, with a weirdo in a suit and sandshoes demanding to know how *I* got on board!

"Turns out the weirdo was an alien called the Doctor, my fiancé was working for the bad guy, and I was supposed to get sacrificed in a bid to conquer the world with big-arse spiders.

"The next year, I met the Doctor again, and we started travelling together. He had a spaceship, he could travel through space and time. He showed me wonders you can't even begin to imagine...

"Long story short, something happened on our last adventure that gave me the Doctor's memories, overloading my brain. I did mention he was an alien? He had to wipe my memories of our travels, else I'd die. Or become a vegetable, either was possible."

"How can you tell us about this if he wiped your memories?" asked Hermione.

"I'm getting there – it's part of the reason I'm here. So, after that time I lived a normal life, even if I always felt like a part of me was missing. I married an actual wonderful man, had kids, lived a long life. I was nearing the ripe old age of 89 when I died – and then the dung hit the propeller blades."

Neville looked politely confused at her expression, while Harry and Hermione grinned. They knew exactly what she was trying to say.

"So that's my backstory, so you know where I'm coming from. My alien friend, the Doctor – one of his more alien aspects, aside from his having two hearts – don't ask – is that he regenerates into a completely different body when his old one dies. Turns out the accident that gave me his memories, also gave me a regeneration. As it happens, I didn't turn into a completely different person, I turned into my 10-year-old self, I got my own memories back as well as the Doctor's, and I ended up in Cardiff."

"In... Cardiff?" said Neville.

Donna nodded. "I know, right? Near as we can tell, a Rift in Space and Time opened and pulled me through during my regeneration, possibly drawn by the residue of Huon particles, or by the regeneration energy, who knows."

"A rift in... y'know what, I'm not going there," said Harry. "How did you end up getting magic?"

"No idea. The person who found me was Jack Harkness, who monitors the Rift running through Cardiff – again, don't ask. I know him from my travels with the Doctor, although we hadn't met yet from his point of view. Still, he knows enough about time travel that he believed me, gave me a place to stay and a cover. Next thing I know, an owl is delivering a letter. The rest, as they say, is history."

"That is... quite the story," said Neville.

Harry nodded. "I would say it's almost impossible to believe, but then a couple of months ago I wouldn't have thought a magic castle in Scotland at all possible – or, you know, that I might make actual friends, so I'll take it. It doesn't seem like the sort of thing you'd make up, does it?"

"So... when you say stuff like 'you'll get used to it' when referring to an encounter with a troll..." Hermione trailed off, but Donna could hear the implied question.

"I'm speaking from experience, yes. It's surprisingly easy to be blasé about stuff like that after your first couple of monsters. Don't get me wrong, it does nothing about the adrenalin in the moment, but you tend to dwell less during the in-between moments."

The conversation flowed easily from there, with everyone asking her questions about her adventures, or time travel, or the future. She answered them, only omitting some details to spare 11-year-old ears. She was glad she wouldn't have to bite her tongue quite so often anymore, at least while she was with her friends – and what friends they turned out to be! She was still an excellent judge of character. Not everyone would have heard her story and basically shrugged and moved on.

Eventually the topic moved to the troll.

"Who do we think brought it inside?" asked Donna.

"We're working from the assumption it didn't wander in on its own?"

"Nah, in my experience these kinds of beasties tend to be brought in to cause havoc. Usually – not always, mind, but usually – they want to be left alone."

"There are wards in place to keep the bigger animals in the Forbidden Forest away from the school," Hermione supplied. "I read about them in Hogwarts, a History. I don't think trolls are excluded."

"So someone must've brought it in on purpose, and they must have access to the school. No reason to bring it into a place you have no business being. I don't think even a seventh-year could sneak something that big and dangerous inside without causing a whole bunch of alarms, so I'm thinking it's probably a teacher. Any thoughts?"

"But... a teacher wouldn't do that!"

Donna looked at Hermione with raised eyebrows. "Sure they would, luv. I mean, not all teachers, obviously. I think we can safely rule out Sprout, for example, but they're human beings, same as us, with all sorts of motivations. Granted, I wouldn't know what motivation one could have to bring a bloody troll into a school, but here we are. Being a teacher does not automatically make them a saint."

"I think it's Snape," Neville said.

"Yeah, he's a right evil git," answered Harry. Of course, the two of them had it worst from the dour Potions professor.

"He does have the brooding villain look down pat, doesn't he?" said Donna. "But looks aren't everything. Personally, I don't trust Quirrell any further than I can throw him."

"His stutter is worse than mine, Donna," said Neville.

"Your point? You hardly have a stutter left when you're with us. But seriously, think about it. Put yourself into our hypothetical bad guy's shoes. Which of these two acts seems the least likely to get your illicit activities closely examined – the greasy dungeon bat looming in or the poor stuttering fool who jumps at his own shadow?"

The others looked thoughtful.

"Look, I'm not saying it's definitely not Snape. His bullying hardly gets him brownie points, just... keep an open mind, is all. Looks can be deceiving. The Doctor was a master at that – make himself look like a clown or a loon, and bam, before anyone knew what hit them, he'd won. It might not even be either of them, but I hardly think McGonagall would allow a troll into the school. Let's just keep our eyes peeled for anything out of the ordinary."