When Hermione's younger self comes to her office hours appointment, the Pensieve Hermione borrowed from Severus is sitting on her desk.

"Have you ever used one of these, Miss Granger?"

"No."

"But you know what it is?"

"A Pensieve."

"There are two memories I'd like you to watch with me," she says, and pulls a silvery strand from her head. When it's swirling in the Pensieve, she pulls her younger self down and they both fall into the memory of the previous day's Defence class when the students fending off two attackers.

"Assess your performance, Miss Granger," she says when they've finished viewing the memory.

"I didn't hold them off for long, but I did better than everyone else except Harry."

"Is your performance in Defence usually this good?"

"Yes."

"And how do you perform in your other classes?"

"Very well."

"What would you say your professors think of you, Miss Granger?"

"They think I'm a good student."

"Only good?"

"An excellent student. All but one of them, that is."

"Professor Snape?"

"Yes."

"Miss Granger, of the Slytherins, who would you say is the best student in Defence in your year?"

"Malfoy."

"And in Arithmancy?"

"Nott."

"Charms?"

"Greengrass, or maybe Nott."

"Transfiguration?"

"Zabini."

"Potions?"

"Malfoy."

"How do you know?"

"Well, you can just tell."

"And their professors, who mark their papers and exams, they'd be in even less doubt about the merits of those students?"

"Yes, Professor," she says, clearly confused about where this is going.

Hermione pulls out another memory and drops it into the Pensieve. "Let's look at this one, shall we?"

It's the part of the lesson where "Professor Greene" quizzed the class on the material they'd been taught previously. Young Hermione watches herself practically vibrating with eagerness to answer every question, while Nott and Zabini and Malfoy's expressions and body language show when they know the answer, but subtly, without the hand-waving.

When she emerges from the Pensieve, young Hermione is clearly embarrassed. "I understand," she murmurs.

"And do you understand that Professor Snape knows exactly what your abilities are? That he knows as well as Professors Flitwick or McGonagall or Vector just how gifted you are?"

She nods. "Thank you for showing me that, Professor. I hated seeing it, but I'm glad I did."

"Somehow, I thought you might be," Hermione says as she watches her younger self walk out of the office.

It's funny, but her younger self seems prettier than she remembers being. Yes, her front teeth are rather prominent, but the overall effect isn't what she remembers seeing in the mirror when she was fifteen. Was she particularly insecure, or are all teenage girls blinded to their loveliness by the anxieties that plague them?

Her former classmates seem so different from how she remembers them when they sit in her office talking to a professor they've just met. It's strange having Lavender and Parvati speak to her respectfully rather than giggling and ignoring her.

It's odd seeing Ron at fifteen, when her fifteen-year-old self had a mad crush on him. He just seems like a slightly awkward teenage boy, and she can't quite remember what made her see more. Now, she feels an intense love and gratitude, but they're the feelings of a woman who saw him take a killing curse for her, not those of a girl who hopes he might kiss her someday.

When Harry comes in, she's almost overcome with tenderness for the boy she spent so many years trying to protect, but who was doomed from the start. When they were in school she was so used to the scar on his forehead that she stopped noticing it. Now, knowing that a fragment of Riddle's soul is lodged there, she can hardly bear to look at it. But once she and Snape have destroyed the Horcrux, it will be just a scar, and Harry will have a normal life. His worst problem will be a bitchy aunt and bully of a cousin. The skulking about he and Ron and her younger self do under the invisibility cloak will be just normal teenage hijinks. They'll use the Marauder's Map to sneak into Hogsmeade, not to avoid Death Eaters.

The Marauder's Map! How could she have forgotten about that bloody map? She's only been in the castle a couple of days, but it's only a matter of time before they notice two Hermione Grangers on the map, and one of them where Helena Greene should be.

She can't go get it now, because the fourth years are all out of class. There's a Quidditch game tomorrow and she can go to Harry's dorm room then and get it. She just has to hope that he doesn't have occasion to look at it before then.

When Neville when he comes for his appointment, she tries to set her worry about the map aside, since there's nothing she can do about it now. "You did well in class," she tells Neville.

"Thanks, Professor."

"How are you doing in your classes, generally, Mr. Longbottom?"

"Well enough in Defence, really well in Herbology, not so well in Potions."

"Professor Sprout tells me you're quite talented in Herbology, that you could earn a Mastery someday if you wanted to."

"My grandmother wants me to be an Auror."

"Your grandmother got to choose her career. You get to choose yours."

"You haven't met my grandmother."

She has, actually, and knows exactly what he means, but lets him continue.

"Not that it matters." He looks defeated. "For either one I'd need a NEWT in Potions, and I'll be lucky if I pass the OWL."

"You dislike Potions?"

"I dislike –" He stops, realizing he shouldn't blurt out that he dislikes the professor. "I'm just not good at it. I mean, if Hermione wasn't my lab partner and didn't help me, I'd be blowing up cauldrons left and right."

"How do you know?"

"Everyone knows I'm terrible at it. Professor Snape says I'm a complete dunderhead."

"Professor Snape calls most of his students dunderheads, as I understand?"

"Yeah, but especially me."

"Mr. Longbottom, I'd like you to do me a favor. Will you?"

"What, Professor?"

"I'd like you to try partnering with another of your classmates, one who isn't quite as good at Potions as Miss Granger, one who won't act as your safety net."

"What if I blow up my cauldron?"

"Then you'll learn from the experience."

"Professor Snape would go spare."

"So?"

"We'll, he'd…"

"He'd what? Yell at you? Call you names? He already does that. Give you detention? So what? So you scrub cauldrons or slice flobberworms. Professors aren't allowed to hex students. So really, what is the absolute worst thing that Professor Snape could do to you?"

Neville looks at her, realization dawning.

"And aren't a few evenings scrubbing cauldrons worth learning how to brew the things you're growing in Herbology? Using them in potions is mainly why you're learning to grow them in the first place, isn't it?"

"It is."

"Then go in there and make some mistakes and learn. Let Professor Snape say what he likes and have you slice and dice disgusting things in detention, but let him teach you, because he will if you let him."

"I will," Neville grins. "I'm not scared of flobberworms."

"Good man."

He grins. "Thanks, Professor."

She's smiling as she watches him leave, and still smiling when Malfoy shows up for his appointment, right on time.

"Mr. Malfoy, thank you for coming."

The look on his face says, I didn't have a choice, did I? but he sits down and says merely, "Of course, Professor."

"You're good at Defence. One of the best in the class."

He nods in acknowledgement.

"You and Miss Granger did exceptionally well holding your shields while attacking each other."

"Why did you pair me with Granger, Professor?"

"After observing the class as originally paired, I thought she'd likely to give you a run for your money."

He says nothing, just looks like he's eaten something that's gone off.

"You dislike Miss Granger."

"Everyone dislikes Granger."

"Everyone, or everyone in your House?"

"I'm not terribly concerned with the opinions of people outside my House."

"Because she's Muggleborn?"

"Among other things."

"Why are you a wizard and not a Squib?"

"What's that supposed to mean? Professor," he adds.

"Why are magical children sometimes born to Muggle parents, and why are Squibs born to magical parents?"

"No one knows."

"Why are you blond?"

He looks startled, then says, "I suppose because my parents are blond."

"Why is your mother blond?"

He hesitates.

"Your aunt Bellatrix had black hair, I believe?" she says.

"Has. She's still alive."

Oops, she thinks, careful, Hermione. "Your mother's parents, what color was their hair?"

"What does my grandparents' hair have to do with anything, Professor?"

"Humor me, Mr. Malfoy."

With growing impatience, he says, "My grandmother's was black and my grandfather's was brown."

"And yet your mother is blond. Why?"

"Who knows? And who cares? Blond hair doesn't make someone magical, Professor."

"Muggles do."

"What?"

"You asked who knows. I realize it was a rhetorical question, but I'm answering it. Muggles know exactly why your mother is blond. They know because of a science called genetics. Genes are what determine your hair and eye color, your height, whether you're stocky or slim, freckled or not. They determine how intelligent you are, but not what you do with your intelligence. Muggles know a great deal about genes because they've studied them extensively. I strongly suspect that genes determine whether a person is magical or not, and how powerful the person's magic is. I believe there are multiple genes that code for magical ability, which explain blood status – which should more properly be called genetic status because it has nothing to do with blood – as well as the level of magical power and different degrees of aptitude people have with different types of magic."

He stares at her, his mind racing.

"This is just a hypothesis, of course," she continues. "I don't know it for a fact because no wizard or witch has collected any data to test it, or even studied genetics, to my knowledge."

"Why hasn't anyone?"

"Because of prejudice against Muggle science, I imagine."

"How do you know so much about it? Are you a Muggleborn?"

"Halfblood," she says, knowing she'll lose whatever credibility she has with him if she answers otherwise. She pulls a book off the shelf behind her and puts it on the desk in front of him. Mendelian Genetics, the spine reads. "If you're interested."

Malfoy hesitates for a moment, then picks the book up.

Hermione checks the time. "I'm expecting Miss Bullstrode any minute, but I've enjoyed our chat. Keep the book as long as you like, and feel free to stop by during my office hours if you'd like to discuss it."

He doesn't say he will, but doesn't say he won't either. Instead, he nods in the courtly pureblood way that he's let fall by the wayside in her time, and walks out.