A knock sounded at Harry's office door. "Come in!" he called.
"Good evening, Professor—?"
Neville's greeting was cut short by a raucous backfire. He flinched. His wand was in his hand and raised in under three seconds.
Harry wiped grease off his hands using a filthy rag. "Good reactions. Faster than some Aurors!"
Realizing there was no threat in the room — just his eccentric professor and a hulking Muggle engine — Neville re-sheathed his wand inside his pocket.
"Have I gotten the time wrong?" Neville asked.
"Not at all! You're as punctual as possible." Harry finished wiping his hands and took out his wand. "I was just tinkering while I waited."
He levitated the engine, floating it back onto a stand in the corner of the room. Looking back at his desk, the surface of which was splattered with colorful oil, Harry used another charm to clean it. He sat down and invited Neville to take the seat he kept for guests.
"What is that, sir?" Neville asked, eyeing the mess of pipes and pistons Harry had been fiddling with.
"It's an engine!" Harry said. "For cars."
"And what were you doing to it?"
"Enhancing it." Harry grimaced. "Trying to enhance it. I thought that it would work well in a lesson. I picked up a little bit of Muggle mechanics over the years, so I thought, 'How hard could it be to improve an engine with my magic?'" He looked sadly at his fingers, which still sported spots of grease. "I overestimated myself."
Before Neville could say anything, Harry clapped and abruptly changed the mood.
"But none of that is what you're here for! Occlumency. Are you ready to start learning?"
Neville nodded. "I've had a few lessons in the past," he admitted.
"Brilliant. What did you learn?"
Neville tucked his chin against his shoulder, avoiding Harry's gaze. He dressed the motion up as looking at the engine they'd been talking about. "I know that it's about clearing your mind. You want to make it seem empty."
"And I take it your attempts didn't go well?" Harry asked gently.
Neville's head shot back to him. "How did you know, sir?"
"There are more ways to read someone than Legilimency. Don't take a few failures to heart, Neville. Most wizards never learn a lick of Occlumency. They brush it off as too difficult and unworth the effort. If you took a grown wizard off of the street and gave them a month of personalized lessons, I'd estimate only a third of them would be able to learn. Did you have those lessons last summer?"
Neville shook his head. "The first round was when I was seven. We tried again when I was ten. Gran thought it was the perfect skill to practice because it doesn't require a wand. But when she realized I didn't have any talent, we stopped working on the mind arts."
"Augusta…" Harry growled under his breath.
"What was that, sir?"
"Nothing, Neville. Whether it needs a wand or not, Occlumency is advanced magic. In Auror training only basic competency is required, and it's still widely considered the hardest part of general training. A fraction of wizards are competent at it. A fraction of those have mastered it. A child not picking it up does not mean you have no talent. It means someone older than you who should have known better made a very stupid choice."
"But if I'd learned it back then," Neville said, "I would already have gotten so much use out of it."
"And if you learned every spell Dumbledore knows you would have run away with the Triwizard Tournament." Harry shrugged. "Powerful skills are useful. That doesn't mean it's realistic to acquire them. Even at his age, the Headmaster is still learning. I'm no exception, and neither are you. You're still a student. Forget what you feel you've failed at in the past and focus on the future."
Neville squared his jaw, nodding.
"Brilliant. Now, contrary to what some people suggest, there are multiple approaches to Occlumency. None are necessarily better than the others— they simply work better for different individuals. I take it that's not what your tutors suggested?"
Neville had unconsciously tilted his head, his lips parting. Embarrassed that his surprise had been caught, he said, "Both of them tried to teach me to clear my head. They never mentioned any other ways."
"That's what my first teacher was like. I didn't do well. I reckon my attempts were ten times worse than yours, and I was almost twice your age. So again, don't feel bad about your efforts."
Neville shifted in his seat. "I appreciate it, Professor. But I'm the chosen one. With all the effort and money that's gone into giving me extra lessons, I should be as skilled as an adult wizard right now."
Harry almost laughed. Luckily, he managed to hold it in, because that was not what Neville needed to hear.
It was just funny to have someone telling him about the weight of being the Boy Who Lived. Although, in truth, Harry wagered Neville had the heavier burden of expectations. He had a kinder personality than Harry that made him less suited to brushing off other's opinions. Most importantly, Neville had grown up surrounded by his own mythos, and people who believed he had to become a legendary wizard. Harry grew up treated like a burden. If there was any kindness in his life on Privet Drive, it was that learning he was worth something came as a surprise, rather than a bare minimum.
"I'm not sure you realize how hopeless most wizards are, Mr. Longbottom," Harry said. "Remember, Occlumency is still a rare skill outside of Hogwarts. Like you, I thought I had no talent for it, so I put it off until I had to learn. Imagine my surprise when all I needed was a different approach."
"What kind of approach?" Neville asked.
Harry conjured a glass of water. A quick Aguamenti filled it to the brim. "Consider this glass as your mind," Harry said. "The water is your thoughts. The usual approach to Occlumency, especially for beginners, is the one your teachers were referencing. By calming your thoughts, you can clear your mind to any intruder. You can visualize that his way."
Harry moved his wand in a downward line. The water inside the glass disappeared. All that was left was a vaguely hazy cylinder of glass.
"This is the simplest approach," Harry said. "You aren't doing anything so much as creating an absence. Anyone who tries to see into your mind will hit a wall and know what you've done."
Neville watched the glass curiously. "Then what are the other approaches? And if this is the easiest, why would anyone start with something else?"
"Because doing things this way requires suppressing your emotions. That's easier for some people than it is for others." Harry smiled ruefully. "I was horrific at it when I tried. Having your mind invaded is the ultimate violation of privacy. It feels horrific, and knowing what they're doing, while struggling to stop them, is enraging. As soon as I got that angry, this method was useless for me."
Water started to appear in the glass again. At first it accumulated slowly, but soon the rate sped up. It didn't take long for the glass to be full again— an undefended mind.
"It made me think," Harry said. "There are so many different personalities out there. I couldn't be the only one who wasn't suited to suppressing my emotions. Instead of forcing everyone to take the same path, it would be better to focus on different strengths."
Neville looked interested as he waited for Harry to explain.
"What do you think your best trait is?" Harry asked.
"I'm a Gryffindor, so… bravery?" Neville suggested.
"A reasonable answer. Think of some of the scariest things you've been through. One of the portraits in Dumbledore's office mentioned facing off against a basilisk? Someone less brave might collapse if forced to stand in your shoes. So imagine this is that memory."
Harry separated a centimeter-thick ring of water. He separated it from the rest of what was in the glass, levitating it just above the glass's rim.
"What happens now if someone tries to get into your mind?" he asked.
"They have to go through that memory," Neville said.
"Exactly. If you can bring that memory to the front of your mind, breathe life into it through focus and a dash of imagination, suddenly you have a shield. If they're any less brave than you are, they'll recoil. That's all it takes to end a Legilimency probe."
"I see!" Neville looked up from the glass, meeting Harry's eyes. "But that must be harder than it sounds, right? Otherwise, Occlumency wouldn't be so rare."
Harry smiled. "Yes. It's much easier to say 'bring a memory forward' than it is to actually do it. The hardest part, though, is the enhancement. Memories are vague and lack immediacy. A Legilimens won't feel like they're reliving what you show them unless you can wield your imagination to fill in gaps. You can use this method with an entirely fake memory, but that's even more advanced. You are, in effect, telling a lie. No, let's call it an embellishment. If you can't sell the terror that you felt back then, you won't test their courage."
"What if they're braver than I am?" Neville asked.
"Then find something else that will make them flinch. If you're smarter, shove them into the hardest puzzle you ever solved and trap them there. If you know you've done something that made them mad, force them to relive it. Legilimency is as delicate as Occlumency. A surge of rage will snap the connection as surely as fear."
"I think I get it," Neville said. "I mean, I don't know if I can do it, but…"
"That's what lessons are for. There wouldn't be much point if I just had to explain it once," Harry said.
"Is this the Occlumency method that you use, Professor?"
"Ah…" Harry scratched his cheek, running his nails through the stubble. "Well, I use a version of this…"
Neville's earnest gaze was too much; Harry didn't have it in him to duck the question. He sighed.
"I'm especially sensitive when it comes to having my head invaded. That's what made my first attempts at Occlumency such a train wreck. So the method I found was to hurt the other person. I change my method depending on who I'm dealing with. If I don't know much about them, I use a false memory of their body in, err, not the best state. If I'm more familiar with them, I sometimes take a different approach. Maybe they're especially close to a sibling or their own child. In that case, I'd picture the treasured person in their place. Or, if they have a terrible phobia, I might use that."
Harry laughed awkwardly. Neville's gaze wasn't too judgemental luckily, more taken aback.
"That sounds… effective," Neville said.
"Oh, very. But because it relies on creating memories from scratch, it's a particularly advanced approach. For now, let's start with your first suggestion and work around your bravery." Harry Vanished the glass he'd used as a visual aid. "First, start by picturing the memory you want to use. Meditate on it. When you feel like you have a firm grasp, I'll launch a gentle probe. Once you can repel that, we'll gradually raise the intensity."
Neville took forty minutes before he was ready to face a probe. Harry waited patiently for as long as he needed. Before their lesson, Harry had cleared his schedule by getting ahead on work. If Neville wanted, they could work the full three hours until curfew.
"I think I've got it Professor," Neville eventually said, cracking his eyes open.
Although he didn't need it, Harry lifted his wand to let Neville know he was starting. "Legilimens."
As promised, Harry entered Neville's mind gently. Looking around, he found himself in Hogwarts' depths surrounded by cobwebs and looming pillars. A statue cast its shadow over him in the light of scattered torches. Not far from the statue's feet, a flickering shimmer almost looked like a human. A teenage girl lay knocked out by its feet.
"The girl will die. I will also kill you now!" the shimmer said.
Something rumbled. A shape came out of the statue. The jaw unhinged to let it slither through. Because the memory was from Neville's point of view, Harry was seeing it from his eyes, which hastily averted themselves. You couldn't see the Basilisk, but you could hear it. The sound was several magnitudes louder than it should've been. Each slithery movement made a sound like a waterfall.
"Now you are going to die very painfully," said the human-like shimmer.
Harry's point of view scrambled behind a pillar. Memories viewed inside the mind were chaotic compared to Pensieves, one of the reasons that the magical tools were so valuable. Even if someone was trying to show a memory, unless they had a grasp of Occlumency, it was bound to come out wild and difficult to grasp even for a good Legilimens.
"This is a solid rendition for a first try," Harry said. "But not quite good enough."
The echo of Neville he had been seeing things from moved one way. Instead of being dragged along, Harry focused all of his attention on details.
The basilisk's noise was still too loud. There was no way it could've been this loud. It was so obviously magnified that it was wrong. Harry calmly stepped out from behind cover, wresting control of the memory.
Ginny Weasley was passed out on the floor, but she kept changing. Sometimes she looked the way she did now, as a thirteen-year-old in her third year, before changing into an eleven-year-old version, continuously going back and forth. The Horcrux fragment of Tom Riddle next to her yelled a threat.
"You are going to be eaten! It will hurt you a lot!" he said.
"Riddle is a lot of things," Harry said. "A poor speaker isn't one of them. He has a silver tongue even when he's describing how he'll murder you."
The memory froze. Cracks appeared, starting around the three errors Harry had identified. The fissures, glowing a dull gold, spread, until the entire memory shattered, sounding like cracking glass. Harry sensed the path deeper into Neville's mind.
Instead of following it, he pulled back.
Harry's consciousness returned to his office. Only seconds had passed. Neville gasped and leaned forward in his chair, supporting himself with his hands on Harry's desk. Harry conjured another glass of water, this one for drinking, and slid it to him.
While Neville guzzled it, alleviating the uncomfortable feeling in his head, Harry talked him through how it went.
"The errors were minor for your first try. The worst of them was the girl with you. Ginny Weasley, I presume?"
Neville nodded tiredly.
"She changed ages," Harry said. "Whether she looks eleven, fourteen, or eighteen won't make a difference to a Legilimens. They weren't there, they don't know how old she should be. But anyone can tell it's not right if she's changing that way. Stability is the most important thing. Next, the sound of the Basilisk was too loud."
Neville shivered. "That's how I remember it. Every move sounded deafening."
"Probably because you couldn't look at it. Adrenaline will do that to you. If you'd like to keep using this memory, there are two approaches you can take."
Neville set the glass down and raised his head. "Two? Shouldn't I make it quieter?"
"That's one of the options. But remember, you're trying to scare the opponent. Either make the noise realistic, or turn it deafening. They might notice that it's too loud, but that's only if they don't recoil in the first few seconds. I'm saying that you can tailor your defenses into a single moment of terror, or a growing feeling of suspense."
Neville nodded, mulling it over in his head. Harry smiled at how seriously he was taking this. Most likely, he'd already considered that Occlumency might help him escape the nightmares he'd been plagued by. Speaking as someone who had been in his shoes, Harry could say just how hard it was to function with restless terror-inducing sleep.
"Finally… You don't remember what the spirit was saying, do you?"
Neville blushed. "I tried my best to get it right."
Harry nodded. "For this, you shouldn't. It's impossible to get the exact words years later. All that was left were general impressions, things like, 'I'll kill you!' and 'You'll be in pain!' That might be what he meant, but they aren't scary. Think of the most chilling threats you can come up with and make it say those instead. It doesn't matter if the spirit never said them. Things like words, which get hazy over time, you're better off fictionalizing. Now, would you like to try again, or are you too tired?"
There was no judgement in Harry's voice. Failed Occlumency defenses brought on short-lived but nasty migraines. Neville chose to keep going. They ran through the defense twice more with negligible improvements.
"One more, Professor!" Neville said when Harry's last probe ended the same way as the first two.
"No, I think that's enough," Harry said.
"I can handle more!"
"Could you grab me one of those newspapers?" Harry pointed to a stacked shelf on the other side of his office. "If you bring it here, we can give it another go.."
Neville looked confused, but wasn't willing to lose this opportunity. He hopped to his feet and jogged to where Harry pointed— until, two steps in, he tripped over his ankles and slumped forward.
Harry caught him with a charm before he could hit the floor. As he was levitated back to the seat he left, Neville blushed bright red.
"I'm all for willingness to learn, but we all have limits," Harry said. "Sit with me for a few minutes until your head clears. Then, head to your dorm and get to bed."
"Yes, sir," Neville mumbled.
Harry refilled his water, which Neville had already emptied once, and Neville gratefully sipped on it again. Humming to himself, Harry took out a pile of assignments from his fourth years and plopped them in front of himself. He grabbed a quill as if to start grading, but spoke instead.
"I'm prone to talking out loud while I work. Since you're exhausted, feel free to ignore my rambling."
"Alright, sir," Neville said, his eyebrows furrowed.
"As you'd know, I'm currently on academic probation from the High Inquisitor—"
"It's awful. She's the one that's wrong," Neville said hotly.
Harry acted as though he hadn't heard him. "She paid me a visit a handful of days ago. Shockingly, she was willing to keep me on the staff despite our past disputes! All I have to do is tell her any information I might come into about a certain club started and run by students."
Neville's fingers wrapped tighter around the glass he was holding. "If you did hear anything about this club, would you go to her…?"
Harry snorted. "I'd sooner leap from the Astronomy Tower with my wand snapped in half." Neville looked relieved, but Harry kept talking. "Unfortunately, I can't imagine I'm the only one she's tried to cajole." He peered at Neville through his glasses. "To quote the High Inquisitor's predecessor, stay vigilant, Mr. Longbottom. Discovery will not end well."
In Harry's time, Umbridge sent Dumbledore on the run when she busted the DA, but even that was better than it could have turned out. Marietta keeping her face covered and Kingsley Shacklebolt's quick thinking narrowly mitigated the damages. Neville swallowed under Harry's heavy look.
"I understand," he said. "I'm already being careful, sir. She's monitoring my Floo calls. She was reading my mail, too, until Gran figured that out and sent a jar of pegasus dung charmed to explode at the touch. It never got to me, and Umbridge was missing all of that morning. She still smelled slightly when she showed up again. I'm pretty sure she hasn't touched my mail since then."
Harry poorly disguised his laughter as a cough.
"Well, try to confide only in those you can trust," Harry said. "Ron, Hermione… Susan."
He winked at Neville as he said the redhead's name, but Neville only looked confused.
"I will," he said, "but why did you single Susan out? She's not even in my house."
"Well, yes, but if you can't trust your girlfriend then who can you trust?"
Neville blushed harder than when he lost his footing after their lesson. "Susan's not—! We aren't—! She's just a friend!"
Harry stared at him. "Do you hold hands with all of your friends that way? During our class on Muggle sports—"
"We're just close!" Neville said. "There's nothing there! Nothing at all! It's… You don't believe me, do you?"
Harry shrugged. "Of course I trust my student's word," he said, but he must not have done a good job injecting confidence into his voice, because Neville hung his head.
"We're not supposed to be a couple," Neville said. "With my reputation and her aunt's job, it would only cause trouble. I know how she feels about me, and Merlin knows how I feel about her, but nothing good will come of it. So we're friends. Just friends."
Harry actually leaned over and patted Neville's shoulder. It wasn't the most professional gesture, but he felt like the kid deserved it.
"That's mature of you," Harry said. "Although, if your intention was to seem more distant toward each other, perhaps the acting could use a little bit of work."
"...That's what Ron and Hermione said," Neville admitted his blush making a comeback.
Harry judged Neville was already getting enough teasing without any input of his own. "Now, if you were going to start a club to teach your fellow students — which, of course you wouldn't, because that would be against the rules — how do you believe it would go for you?"
"I think it would go surprisingly well, Professor," Neville said. "I think I would have a lot to improve on when it comes to teaching, but other students would really appreciate the effort I put in. I think it would even help me learn defense better because it would make me think about it in new ways."
"Defense, or any other subject the club might focus on," Harry said.
"Right. Of course."
Harry smiled, steepling his fingers. "In that case, I'm glad to hear that things would be going so well. I'm sure there would be challenges, but nothing you couldn't overcome. If you have any questions about how you might handle any prospective challenges, be it on teaching or content, I'm sure I could think things through with you."
"Thanks, Professor," Neville said. "It means a lot."
Harry smiled. "In that case, I'll see you next Wednesday. By then, we'll make sure your basilisk has me pissing my pants."