No update next week so I'm posting this now.
The first few weeks of Hogwarts passed in a very boring fashion! The Doctor was contemplating breaking out. She was keeping entertained by conducting experiments with artron energy. Ever since she'd seen McGonagall transform into a cat, she'd been obsessed with figuring out how her body's mass could change so much.
So far, she theorised that artron energy could be used as a sort of compression field but it was lot of mass being compressed so she wasn't so sure. She'd also thought that perhaps it worked dimensionally - there was a cat in McGonagall and in the cat there was a McGonagall. But where did the cat come from? Did a being reside inside everyone? Or was it only Carrionites? Beings with artron energy? So many questions!
And while she was on that, how exactly did Transfiguration work? It seemed to break the rule of conservation of mass but the Doctor knew there was probably some science behind it. People probably thought the TARDIS was magic after all.
Anyway, she was completely going out of her mind with boredom. She just wasn't built to go to school. All the rules, obligations and worst of all having to sit still in a classroom! It was fine when you were a teacher - you got to move around. She missed being a teacher. Shame she had to look eleven.
But... it was a magic school. A sentient magic school. Hogwarts (the castle) was great! She should really introduce her to the TARDIS! Idris and what was the school's name? Idris the TARDIS, ? the school. Didn't sound very good. What could she call her? Hogwarts was a castle. What do you call a castle? A cast-le. A cas-tle. Cas. Cassie?
The castle projected a sense of amusement. 'Got any ideas?' she asked kindly. This incarnation seemed less grumpy than the previous ones.
After some hesitation, presumably the castle was considering it, the sentient school decided to accept the name. The school wasn't sure what to think about their previous name but was glad they were being offered a choice this time.
The Doctor grinned energetically. "Then it's nice to meet you Cassie the castle. I'm The Doctor, a Time Lord alias Hermione Granger."
It turned out to be a very good thing that the Doctor had made friends with the castle because a few days later, she finally got the catastrophe she was expecting. That was the problem with helping people - you had to be the good guy so guess who all the bad guys tried to kill.
It was always good to have a sentiment being on your side - Cassie at least if not Idris. Sadly, the TARDIS was parked near Kings Cross station. Or should the Doctor say in?
Either way, when Cassie warned her trouble was incoming during dinner, the Doctor had been expecting it.