"I don't know if we're supposed to, but there are less students this year."

"There are? Is it because of the, uh. The thing. Last year."

"The war. People are probably going to talk a lot, about it. I mean, no one will say anything about it, they'll just argue about other stuff. If you hear anything about my family...talk to me first."

Is it time to pay attention to the professor? Hopefully it's that time.

The professor ... is late. Charming. 

Right. Naomi managed to blow her cover to a stranger. Again. Good thing he seems to be nice about it too. Or maybe he doesn't think she's a muggleborn? There are lots of reasons someone could not know about the war.

... better not to bring it up.

"Okay," she says.

"How did your family deal with it? Did you move away?"

"I, uh, no. I was, we were, uh, hiding. How about yours?"

"We weren't here for most of it." 

A woman strolls through the door and down the center aisle. The windows, once open, are now shut, with huge conjured curtains blocking the light. By the time she arrives at the front of the classroom the students can barely see the blackboard.

"Hello. My name is Professor Rivers. I regret that I was unable to introduce myself at the feast. Today is going to be a practical lesson, so we're going to get these tables out of the way. Everyone, move towards the walls. Quickly!"

Derek moves, and surprisingly quickly. 

"What do you think she has planned?" 

"Maybe we get to try dueling!"

Professor Rivers, meanwhile, is Vanishing the desks in the room, one by one. When she's done she orders everyone to spread out and find spots on the floor.

"Do you want to be partners, if it's that? I'll stand opposite you." 

"Sure!"

"Alright. Thank you for being cooperative, everyone, and welcome to Defense Against the Dark Arts. Traditionally in magic Defense courses you learn defenses against simple hexes and jinxes in your first year, then defenses against certain malicious magical creatures, and at the OWL level, more comprehensive defenses against your fellow witches and wizards, including how to recognize curses.

I will be teaching those subjects since they are the ones on which you will inevitably be tested. But they will not be the core of my Defense classes. It is useless," she says, eyes blazing, "to have all this information and be caught off-guard before you can even use it. Therefore, this first lesson will be in basic awareness. You will learn to pay attention to your environment in a way that will allow you to react appropriately."

The rest of class is spent on various meditation and observation exercises, which they'll be "repeating throughout the term".

Derek proves good at paying attention. It seems to come naturally. 

Naomi is less good. She especially struggles with the illusion charm that gives sensation to the five senses at once -- she has trouble paying attention to every source of stimulus instead of one, at most two.

For the last portion of class the professor puts the chairs back and encourages students to get out their parchment. She conjures an odd, misshapen metal object. "I will Vanish this object in ten seconds. Write down as much detail as you can about it and turn your paper in to me before you leave. Don't forget your name!"

Naomi tries a drawing, mucks it up, scowls, and starts listing features.

Derek notes down a detailed description of what it looks and smells like. He has no guesses about function, but he didn't miss anything sensory. 

And class is over! Professor Rivers collects their papers and waves them towards the Hall to eat lunch. 

"That was haard. How did you do, Derek?" Naomi is collecting her things. She could see him writing a lot from where she was sitting but didn't pay attention to the content. 

"I think I did well, if it was about paying attention. I'm good at that. Better than most other things, so maybe I'll be good at Defense." 

"She said it was about paying attention. So probably. Ugh, how do you do it?"

"My senses are better than most people's. I hear well, see well. My whole family is like that. Focusing is just something you have to learn, if you want to be good at it."