"Granger."
Sherlock was sitting on the arm of the couch, staring at Hermione intently.
"Granger."
"What do you want, Sherlock? I'm busy." Her summer term exams were just a week away, and she had been revising like a madwoman. She was determined to make it through her program sooner rather than later. Plus it gave her an excuse to ignore Sherlock.
Shortly after she moved in, Sherlock had taken to keeping relatively sober and accompanying her as often as possible, trying to prove that she was, in fact, one of his brother's minions. On the plus side, this meant that he took meals reasonably regularly, and spent considerably less time slowly killing brain cells. On the minus side, his constant attention could be very irritating. But she had spent six years living in Gryffindor tower as the best friend of The Boy Who Lived. She was quite accustomed to constant interruptions of her work, a complete lack of privacy, or being followed around and watched. For rent-free housing, she would put up with much worse.
"I have finally decided that you aren't a spy."
She looked up. "Well, I'm glad to see it only took two whole years, Master Detective. Go play with your chemistry set or something. The adults in the room are trying to get their work done."
"Don't you want to know why I've decided you aren't Mycroft's spy?" He sounded somewhat put out.
"Well, if you didn't believe it when your mum invited me to your cousin Cherie's wedding, and you didn't believe it when Anthea broke in here on Mycroft's orders and I freaked out and punched her in the face, and you didn't believe it when I've spent twenty-four of the last twenty-six months actually studying psychology, which is the reason I am here, I don't really know what it could be, and no, I don't really care." She went back to her notes, rolling her eyes at her impossible cousin. "Madman," she added under her breath.
"I'll have you know I'm a high-functioning sociopath, thank you very much," Sherlock quipped. "Emphasis on the high-functioning bit."
Hermione couldn't help but snort at that. There were so many things wrong with that statement. First off, sociopath wasn't even a real psychological term. And Sherlock was far more bipolar than psychopathically inclined. And he could only be considered "high-functioning" about two days out of every five, even when he was wrapped up in a mystery, such as the Case of the Cousin Who Might be a Spy, rather than spending weeks at a time drugged out on the sofa or tracking down illegal materials for experimentation purposes.
"Whatever helps you sleep at night, Holmes."
"Don't be ridiculous, Hermione. Who sleeps at night?"
He had a point: it was four in the morning, and neither of them had gone to bed yet. "It's a phrase, idiot, so I suppose it is implied that normal people, you know, those lucky sods who still have regular bio-rhythms, sleep at night."
He ignored this. "Your trunk. I can't open it." She raised an eyebrow. The trunk was magically sealed. There was no way he would ever be able to open it. She was, quite frankly, surprised it had taken him this long to try, though. "Don't look at me like that. It didn't take me two years to try, it took two years to admit that I can't." Ah, that explained it.
"And? How does that prove I'm not a spy?"
"It's impossible! Even when the locks are clear, it doesn't open. There are no secret panels or pressure plates. It's apparently made of unlaminated oak, even under a hand lens, but I can't damage it in any way, with physical force, from a knife to a sledge hammer to a contained explosion, or acid etching or burning! The fittings look like brass, but they won't melt, even under an acetylene torch, and they don't react to anything, it's like they're made of gold or something, but just like the wood, you can't damage them, even with a hammer and chisel. It doesn't appear to be held down in any way, or attached to the floor or wall – I managed to slip a bit of string all the way down behind it and under it. But I can't lift it or move it at all, even the tiniest bit. Even if it were entirely full of gold bricks, I still ought to be able to shift it slightly, and if that were the case, I'd never have gotten my string under it."
Hermione smirked. "So I can't be a spy because I have an impossible trunk."
"No, you aren't a spy because Mycroft's spies aren't interesting enough to have a trunk that defies the laws of physics."
"Okay. Glad we've cleared that up. Can I go back to revising, now?"
"NO!" Sherlock was glaring at her in a surprisingly accusatory way. "Tell me what's going on!"
"I'm legally obligated not to tell you what's going on," she explained calmly. "And to take all reasonable precautions against you figuring it out." She wasn't actually trying to keep her magic secret from him. If he managed to figure it out despite the fact that she had followed all the ministry-recommended precautions, she would gladly answer his questions. She supposed he would, in fact, get there eventually.
She could see his mind working. He knew she didn't normally give much thought to legal obligations unless she thought they were important or sensible. "You didn't deny it."
"Well, I could hardly deny something that can be objectively observed, or at least deny it and expect you to believe me."
"And you're not surprised or irritated that I tried to blow up your trunk."
"It's not like you succeeded."
"No, and you knew I wouldn't."
"I would have noticed by now, if you've really been trying to break in the entire time I've been here and you were capable of damaging anything."
"But you weren't worried. So either you're a complete psychopath, or you know what's going on."
"Of course I know what's going on: It's my trunk. I'll even give you a hint," Hermione grinned. "Your favorite quote, about how when you've eliminated the impossible, the improbable must be true? It ought to have a corollary: When you've eliminated every explanation as impossible and the phenomenon remains, it's time to revise your definition of impossible."
"What kind of hint is that?"
"The basic premise of the scientific method. Go back to Kuhn. You might need to consider a major paradigm shift in order to figure this one out, that's all."
"So… Right. Okay then. And don't think I didn't notice you not addressing the psychopath comment."
She honestly wasn't sure anymore if he really did think she was a psychopath, or if he was just saying it to irritate her, but he had been accusing her of it for months, ever since he had finally asked what she was studying, and why (psychology, because people are strange and fascinating creatures). She had given up denying it. "Can't prove a negative, Sherlock."
And with that, Sherlock retreated into silence. Hermione returned to her revising, and life resumed its normal pace.