Draco, as much as he loathed to admit it (not that he ever would), was rather shocked.
Hermione Granger didn't know how to make a patronus? Who would have ever thought that the brightest witch of their age didn't know something that the nutshell Potter did? Being absolutely honest, anyone who had seen Potter in potions class would admit that his streak of wins was more out of sheer luck and good timing than anything else.
Regardless, this was not the most prominent thought wandering around Draco's mind at the moment. No, it was not that 1) he was rather annoyed that it was McGonagall coming to fetch the two of them out of the room, and that his own head of house had so far showed not even a bit of concern, or 2) that Granger had considered his exclamation of how she was the smartest witch of their age flattery and not the downright truth, or 3) his slight amusement in the fact that McGonagall's patronus was a cat.
No, it was none of these things. Instead, it was the one that probably (hopefully) anyone in his or her right mind would be most bothered by. Yes, this was it, reverberating between his ears: neither of us know how to make a patronus, and at the moment that's out only means of getting out. Only a tad bit of a problem. Obviously, the fact that they might not be able to send a message in return had not crossed the Professor's mind.
Draco let his eyes scan the room. Unfortunately, the possibility of simply sending the silver cat back to her owner with a new message was long gone, as the cat had become a wisp of silvery light the moment McGonagall's voice had finished. Draco's eyes eventually settled on a small gathering of books on the ground by the Door Wall, as he had come to refer to it. Granger must have dropped them when they had sprawled into the room.
Wait, Draco's mind jerked to a halt. What kind of books?
Over there in a flash, he picked up the first book he could lay his hands on. Defence Against the Dark Arts: The Basics for Beginners. Maybe? But patronuses were highly advanced magic. Not for Beginners.
Next book: The Past of Fighting the Dark. Very Granger-like, searching the history of Defence Against the Dark Arts. No use for this.
Again: The Complete Guide to the Dark Arts and Their Defences. Complete guide? Sounds more promising than Professor Binns' take on the topic. Might as well take a look.
Table of Contents: Nothing there. Index: P…Pa…Pat…Patronuses—page 392
Score!
Malfoy let out a small whoop, his mind vaguely registering that he had spooked Granger quite well out of her skin.
Page 392 didn't have nearly as much writing on it as one would imagine for such an advanced technique. Quickly absorbing the information, Draco read: Patronuses are highly advanced magic, used as a defence against Dementors, the guardians of the wizard prison of Azkaban. The patronus is casted with a focus around the feeling of happiness, which makes it very difficult to perform in the face of a dementor. A simple incantation of Expecto Patronum, while focusing on a happy memory will result in a silver figure of an animal to come from the tip of the wand.
Exactly what he needed. But before Draco could blink, he had been unceremoniously knocked back to the floor. He slightly registered the fact that a high-pitched, ecstatic voice was talking at a speed barely comprehendible.
"Books, the books! Oh, why didn't I think of these before! I checked them out for DA, there's got to be something about patronuses in here!" The voice continued on, but in addition to being very fast, Draco simply didn't want to hear it, so nothing more was registered.
For a moment, Draco just decided he didn't want to bother with the arguing and he just stared at the ceiling of the dark room while Granger went into book mode. His quiet time, however, was broken when the book in his lap was snatched away from him, and with that his little resolve snapped.
"Hey! What do you think you're doing, Granger? That was my book!" His voice got loud as he shot up into a sitting position. The girl didn't look up from her book, nor did she seem to register his complaints at all. Draco's mouth dropped, ready for another shout, but before he could do so Granger's head whipped up, accompanied by a deadly stare.
"If you think that getting us into an argument is going to make this situation any better, I beg you not to think that. The only possible way we're going to get out of here is to cooperate-"
"Cooperating typically means not snatching books out of people's laps!" Draco interrupted.
"It's my book Malfoy, and I'll snatch it out of whatever lap I feel like!"
"Didn't your mummy teach you any manners? Share. And no grabbing either!"
"Didn't your mum ever teach you that it's polite to ask to borrow someone else's possessions, instead of just taking them?"
Malfoy started to open his mouth in protest, but Hermione cut him off before he even started.
"Here we are! 'The patronus is casted with a focus around the feeling of happiness, which makes it very difficult to perform in the face of-'"
"I know what it says Granger! I was able to read it before you snatched it out of my hands! If you would have waited half a second, I could have told you what it said! We could be practicing the spell by now!"
"Fine," snapped Hermione, "if you've already read it, why don't you tell me what it said."
"We need to think of an incredibly happy thought."
"Hard to think of happy thoughts when I'm stuck here with you Malfoy," muttered Granger under her breath.
But Draco caught the rude remark, and sneered at her. "Listen Granger, I don't want to be here as much as you do, possibly even more! But if we want to get out of this blasted room one of us has to learn to cast a bloody patronus, and to do that we have to be happy, and to be happy, we have to cooperate with each other."
"Fine. Let me finish reading the description, and then we can start practicing."
"Fine."
"Fine."
And with that, the obnoxious bushy haired girl sat down and resumed reading where she left off.