Harry was still a little in shock over how transfiguration had gone. He had never seen McGonagall do anything like that and he was unwillingly reminded of Snape’s potions class, but with McGonagall taking the role of Snape and Eli the role of Harry.

All the Gryffindors had decided to stay back to wait for Eli to be released by McGonagall and Harry was listening to them speculate over what had happened.

Seamus had suggested ominously that Snape had gotten rid of the real McGonagall somehow and was now taking her place to hide the evidence. “I’m just saying,” Seamus insisted, “that McGonagall wasn’t there when Snape announced he was leaving, and after that is when she started acting differently!”

Hermione scoffed at this.

“Wait a second Hermione, he might be onto something,” Ron said excitedly. “Remember when Eli was telling us what happened yesterday? He was hit by an unknown spell, then he went to go see McGonagall. She keeps coming up!”

“Oh my god, he went to see her because she’s the professor he’s had the most contact with. I don’t know why she was so...odd today, but I’m sure there’s a perfectly reasonable explanation,” Hermione said, clearly exasperated.

“It just doesn’t make sense for McGonagall to single out one of her own students like that! Something must have happened to her, and with Snape’s mysterious disappearance, he’s clearly a prime suspect,” Seamus said.

“Especially since McGonagall treated Eli like Snape usually treats Harry, it would make so much sense if McGonagall was really Snape in disguise,” Dean added thoughtfully.

“If McGonagall were really Snape in disguise, why didn’t he go after Harry like he usually does? Harry was right there, but was practically ignored for the whole lesson like the rest of us were. What reason would Snape have to target Eli over Harry?” Hermione said reasonably, but with an edge to her voice that Harry knew meant she was getting annoyed.

Seamus said, “Because he clearly doesn’t want us to know it’s him! Targeting Harry would be wildly out of character for McGonagall, but Eli is new so Snape probably figured it was safe to go after him instead. Plus Eli is still a Gryffindor and Snape may hate Harry the most but he does hate all Gryffindors at least a bit and would probably take any excuse he could get to harass one.”

Honestly, Harry had no idea what was up with McGonagall. She had definitely been behaving strangely, but he had a hard time believing that Dumbledore would let Snape get away with pretending to be someone else like that.

Then Eli finally stepped out of the classroom.

Harry was glad that he appeared to be in one piece and not unduly distressed. The lesson itself had been distressing enough, but then she’d had to hold Eli back on top of that.

“What happened, Eli?” Seamus leapt in to ask, just a bit too excited, given the circumstances.

Eli took a half step back away from Seamus, towards the now closed door, “Nothing much, she’d had a bad day or something, and she just wanted to apologize and say it wouldn’t happen again.”

“See?” Hermione said smugly, “there was a perfectly reasonable explanation.”

“Until I see McGonagall and Snape in the same room at the same time, I have no choice but to believe that Snape took McGonagall out and is now masquerading as her,” Ron said firmly, crossing his arms for emphasis.

Seamus crossed his arms too and said, “Yes, exactly.”

Eli paused for a moment then said, “What.”

“We’ve got to get going or we’ll be late for Herbology,” Hermione said, grabbing Eli’s hand and tugging him down the hallways, “I’ll explain on the way.”

Harry quickly followed them, rolling his eyes at Ron as they went.

Hermione summarized Ron and Seamus’s theory on what happened to McGonagall. Her tone had left little doubt about her personal stance on the theories, and Ron and Seamus had taken great delight in correcting her for the most minor of errors. Harry had simply enjoyed watching the look on Eli’s face grow more incredulous as they drew nearer to the greenhouses.

The rest of the day passed simultaneously too slowly and entirely too quickly for Harry. He had been so distracted by other things like McGonagall and class and Ron and Seamus’s theories that he’d forgotten to be nervous about the upcoming DA meeting. Until all of a sudden, it hit him in the middle of lunch.

He was hardly able to pay attention to Charms thanks to his anxiety, and when the class finally ended, he was one of the first people out the door. Ron and Hermione were close on his heels out the door, and once they were in the hallways, Hermione said, “Are you okay, Harry?”

“I’m fine,” Harry said absently. Then he processed who’d asked and continued, “I’m just nervous about the DA meeting.”

“You’ve got this, mate, you did so well all last year, this is just the same thing with a slightly bigger audience,” Ron said reassuringly, leaning against the wall next to the Charms classroom door.

Harry realized that they hadn’t been there for the meeting with McGonagall.

“You guys know that McGonagall is going to be overseeing the lesson, right?” Harry said.

Eli exited the classroom at a sedate pace and paused beside them.

“Hey y’all I’m off to the library to get some work done, so I’ll see ya at dinner,” Eli said before hurrying off towards the library.

Harry said, “See you,” to Eli’s back before he refocused on Hermione and Ron.

“Since when?” Hermione asked with a frown, “we never needed supervision before.”

“Before we were running the club illegally and without approval, but, you know, this time we wanted to do everything above board. To make sure as many people as possible would come. And getting the club officially sanctioned is the best way to do that. So, would you mind helping me prepare for the meeting? I want to make sure I know what I’m gonna say…” Harry trailed off hopefully.

It’d be a lot easier to be confident about his preparedness with feedback, and he knew he could trust Ron and Hermione to be honest with him. At least, he could when they weren’t too distracted by each other to notice anything else.

“Yeah, of course! We’d be happy to. Where did you want to practice?” she asked.

Harry set off towards the Room or Requirement, knowing Ron and Hermione would follow him. “I’ve been using the Room of Requirement for practicing,” he said, just to clarify where they were going.

They chatted about nothing in particular as they made their way through the castle.

When dinnertime came around, Harry was feeling much more confident about his ability to give the lesson. Oh, he was still reasonably sure that he would be replaced after this lesson, but he didn’t think he’d horribly embarrass himself anymore.

That is, as long as McGonagall didn’t do something disruptive or out of character. It felt odd to worry about that, but after the class they’d had earlier, he didn’t think his worries were unfounded.

“You know,” Harry said to Ron and Hermione as they walked to dinner, “McGonagall said she was going to ask Dumbledore to make an announcement about the meeting, but he obviously hasn’t yet. I bet he’ll make one tomorrow morning at breakfast, about 12 hours too late.”

“That’s awfully optimistic of you, mate. My money’s on Thursday after dinner. He’ll get the first letter of the day right but nothing else,” Ron said.

“What do you think, Hermione?” Harry asked when it seemed like she wasn’t going to weigh in.

“I’m thinking about it, give me a second,” she said with a light slap to Harry’s arm. A couple moments later in which she dramatically muttered to herself and counted on her fingers, she said, “Okay, I think he’s going to announce it on a Tuesday three months from now, totally unaware that he got the date wrong.”

Harry snorted.

“I guess we’ll just have to wait and see,” Ron said sadly, “it’ll take ever so long to see who’s right. Especially if it’s Hermione.”

When they got to the Great Hall, Harry saw that Dumbledore was seated at the head table. He nudged Ron and discreetly pointed this out.

“He’s not gonna do it,” Ron said quietly, looking at Dumbledore out of the corner of his eye.

“It’s just a coincidence,” Hermione agreed.

They were joined by Eli not long after they settled in their seats. He was a welcome distraction from the mystery of Dumbledore, since Ron was determined to interrogate Eli to get more information that could possibly corroborate his McGonagall/Snape conspiracy theories.

But then Harry’s thoughts turned to what had happened last night, urged in that direction by Eli’s presence.

Harry tuned out the sound of Ron calling Seamus over for further theorization. He was glad they were having fun with this, but he was feeling too anxious to join in.

He was forced to admit that he was grateful that Eli hadn’t meant to say what he did. Even though what Eli had said was true, he thought that he had been making things up- Or something. Harry wasn’t entirely sure how the spell Eli had been hit with worked. And it might be selfish of Harry, but he was glad that he didn’t have to worry about there being someone who knew the truth.

Then he felt guilty because he was benefiting from Eli, and from everyone else for that matter, not knowing and not acknowledging that Harry was what Eli had said he was. Harry was horribly afraid of the moment that everyone discovered that he had been hiding the truth.

He was happy to be startled out of his thoughts by Dumbledore rising from his seat.

Ron dug his elbow into Harry’s side and Harry reflexively retaliated.

“Look-” Ron stage-whispered.

“I can see that,” Harry responded.

“If I could have everyone’s attention,” Dumbledore said with a pause to wait for silence, “I have been asked to announce that there will be a new club meeting today after dinner. That is all.”

He returned to his seat with a flourish.

In the lingering silence after this, the hall could clearly hear Professor McGonagall say, “Albus, you didn’t say what the club actually is.”

Harry groaned quietly and planted his face onto the table. Ron patted his shoulder. Harry reluctantly sat back up to see what he would say next.

Dumbledore got to his feet again and said, “As I was just reminded, the club is called the Defense Association, and its purpose is for students- that’s all of you- to learn how to defend yourselves.” He turned to where McGonagall was seated and said, “Is that good, Professor McGonagall?”

She nodded tightly.

“Then that is all, for real this time,” Dumbledore said with a smile, then resumed his seat.

“Well,” Hermione said, “all of us were wrong.”

“What were you wrong about?” Eli asked curiously.

Harry’s leg started bouncing under the table. He was getting very nervous again about giving the lesson after dinner. He knew the conversation was continuing around him, but he couldn’t bring himself to focus on them.

He just kept thinking about how badly the night could go. If nobody showed up, he would have to sit and watch the Great Hall empty of people until he was sitting with just Ginny, Neville, Ron, Hermione, and maybe Eli. Oh, and McGonagall. All staring at him because he was supposed to be the leader of the club and it was therefore his fault if it failed.

Or, even worse, if people stayed behind for the meeting, but got up and left as soon as Harry started the meeting. Because Dumbledore hadn’t mentioned that he’d be leading it, and if they hadn’t seen the posters or heard the talk, then they wouldn’t know. And then if enough people left, it would start a flood until Harry was left standing at the front of the hall by himself, faced with the disappointment of his friends.

Or maybe Harry would manage to actually get the meeting started, but someone would interrupt and talk about how wrong Harry was getting everything and then everyone would leave because Harry didn’t know enough to be worth sticking around for.

“Harry! Earth to Harry!” Hermione said loudly.

Harry jumped slightly then focused on Hermione and said, “Sorry, what?”

“The tables were cleared and I thought you’d want to know about that.”

Harry was startled to realize that she was right, so he thanked her for informing him and stood from his seat. He needed to speak with McGonagall.

“Once the Great Hall has cleared of everyone who’s leaving, would you mind waiting a couple more minutes then getting rid of the tables?” Harry asked McGonagall as he drew level with her seat at the Head Table.

“Of course,” McGonagall said, “I look forward to seeing what you do with this,” she added, with a kind smile.

Harry returned her smile nervously. He didn’t think his nerves could take further confrontation, so he said hurriedly, “Oh, it’s not that great, don’t get your hopes up too high. I have to go to conjure a lot of beach balls, if you’ll excuse me.” Then he hurried away before she could further respond.

He made it back over to where Hermione and Ron were still sitting at the Gryffindor table. “We should probably get started with the beach balls,” Harry said.

They stood from their seats.

“What’re y’all doing?” Eli asked curiously.

“We’re getting some stuff ready for the meeting,” Hermione responded.

There was a short silence before Eli said, sounding reluctant, “Do you need any help?”

Harry shook his head, and Eli looked relieved as he pulled out a book and settled in to read it.

To Hermione and Ron, Harry said, “You guys get started, I’m going to go enlist Ginny, Luna, and Neville too.”

They nodded firmly and Hermione conjured one of those wading pools designed for small children. Then Ron and Hermione each conjured a beach ball and put them in the pool. Ron continued to conjure beach balls while Hermione turned to the task of magically inflating them all.

Harry turned away now that he’d confirmed they had the situation under control. He hurried down the table to where Ginny was seated with her yearmates to recruit her and then to the Ravenclaw table where Neville was eating with Luna.

All of them quickly agreed to help with the beach ball conjuring, and Harry hurried back over to where Ron and Hermione were still rapidly conjuring and inflating beach balls. With all of them working at it, they soon had a lot of wading pools filled with beach balls.

They were drawing a lot of curious stares from the students still seated in the hall, but Harry ignored them in favor of absently squeezing a beach ball and rehearsing what he was going to say.

In the middle of his third speedrun through his opening remarks, all the tables suddenly vanished, causing all the students that had been sitting at them to land with a heavy thud on the ground. There was a loud round of exclamations and complaints from the students as they got to their feet.

Harry couldn’t believe McGonagall had just done that and his worries from earlier about her disrupting the meeting came flooding back. He briefly wondered if maybe Ron and Seamus were onto something before he shook it off.

He hurried to the front of the room where McGonagall was getting to her feet as well. She must have been sitting in her chair when she had vanished the head table along with the house tables. Harry reminded himself that he didn’t have the mental energy to waste on speculating about her odd behavior off for the time being.

“Did you want to speak to everyone before the meeting starts, or should I just go ahead?” Harry asked a little nervously as he arrived next to McGonagall, who had regained her feet. He had no idea what kind of things she’d say while in this odd...mood, but he still felt like he ought to offer since she was their advisor.

“No, no, I’ll just be off over there,” she responded, gesturing vaguely over her shoulder towards a corner of the room before wandering off in that direction.

Harry stared after her for a brief moment, then turned to face the small crowd of students that had formed in front of where Harry now stood. He was grateful that the head table was on a slight dais, because otherwise no one would be able to see him.

Many of the students were Gryffindors, which made sense, so it was easier for Harry and his friends to spread the news to them since they all lived together. But Harry was gratified to see that there were a respectable number of Ravenclaws and Hufflepuffs- about an even number of each- and there was even a small clump of Slytherins off to the side.

Then he realized that he was awkwardly standing in front of the quiet group of people, who were clearly waiting for him to speak, so he cleared his throat and began to say what he’d been planning to for so long.

“Thank you all for coming to this first meeting of the revamped Defense Association. We were founded last year as a reaction to Umbridge’s,” he paused briefly, “ineffectual teaching methods. Then this year, we decided that the extra lessons in defense would be relevant for everyone given the current state of affairs,” Harry cleared his throat delicately before he continued.

“There is some concern over the club being led by a student, me, so this meeting is a bit of a trial run.” He was forced to pause as Ginny, the Gryffindor Quidditch team, and the rest of his friends booed this briefly. He could feel himself blushing and forced himself to ignore it so he could stay on track. “So, I decided that today’s meeting would be focused mostly on learning a slightly rare, but easy spell that I found. This way, I can be sure that the meeting is wrapped up with no loose ends. Going back to the spell, it’s a shield charm called the Clausium Charm.”

He proceeded to explain a bit of the history of the spell, including his own thoughts behind its present rarity. Then he explained the theory of the spell, in as simple terms as he could manage, since there were students as young as second and third years present.

Harry was in the middle of explaining how the shield was useless against most hexes and jinxes when a younger Ravenclaw interrupted him.

“What’s the point of a shield that can’t block spells,” he had said derisively.

Harry considered giving an actual demonstration, but decided not to because he didn’t want to overly derail his plans. Instead, he said to the group, “Hexes and jinxes aren’t the only forms of magic used in a duel. Transfigured attacks can be difficult to defend against since classic shield charms like Protego don’t block physical objects. This charm offers a defense that doesn’t require skill at transfiguration.”

Then he redirected his gaze to the boy who had interrupted and said, “Does that make sense?”

The boy nodded, so Harry went back to explaining the theory of the spell.

“Alright, so with the boring part out of the way, I think it’s time for a demonstration,” Harry said with a smile, before he drew his wand and summoned one of the wading pools full of beach balls. They flew over the students and landed a couple feet in front of him. “Ginny, would you do me a favor and chuck one of these beach balls at me?”

Ginny has been standing off to the side so she hurried onto the dais and over to where the beach balls were and scooped one up. “I can absolutely do so,” she said with a wicked grin, and backed up so she wasn’t right on top of him.

Harry grinned back and positioned his wand hand so he could flow through the wand movements as quickly as possible. He knew the beach ball wasn’t supposed to be able to go very fast, but Ginny wasn’t a Weasley and a chaser for nothing.

She whipped her arm back and sent the large beach ball at Harry. There was a moment where Harry thought it was going to move much faster than it ought to be able to, but when it left her hand, it floated through the air as it was supposed to.

He whipped through the wand movements and enunciated the incantation, “Clausius!” clearly.

Where he pointed his wand after the last wand move, a shimmering, cloudy white, two-dimensional rectangle appeared to reflect the ball back at Ginny.

The beach ball impacted with the shield and bounced back to Ginny, who hit it back towards the shield. The shield reflected the ball back at Ginny once again, but this time she caught it.

“Finite,” Harry muttered, causing the shield to dissipate. “Thank you for your assistance, Ginny.” She smiled at him and hopped back down to where she had been standing, still holding the beach ball.

“Because Ginny was tossing a beach ball at me, and not something more dangerous, I decided to bounce it back to her. That’s why it’s so important to visualize where you want the shield. If you don’t picture the shield precisely, it could be useful or useless, or even dangerous. Which is why we’re practicing with beach balls and not knives,” Harry said with a smile and was gratified when the students responded with a ripple of laughter.

“Let me run through the wand movements and pronunciation again, but slower, just to make sure everyone has it,” Harry said as he exaggerated and slowed the same wand movements he had just done, followed by repeating the incantation. He repeated it twice more because he saw that some of the younger students were miming his motions, and he wanted to be reasonably sure they had it down before he moved on.

“If you all could spread out and pair up, preferably with someone of a different house, that would be great. My friends and I will disperse the beach balls so there’s some within easy reach for everyone. Once that’s all ready, you will all take turns throwing a beach ball for your partner to deflect with the shield or practicing the shield.”

Harry stopped speaking, and the students stood there, motionless, staring at him. “Go ahead and break into pairs now,” he said uncomfortably. And it seemed that was what they were waiting for, because then there was a flurry of motion as they all split into pairs. He jumped down from the dais and started levitating the wading pools around the room.

He saw that Ginny, Ron, Hermione, and Neville were all doing the same thing, and he was glad they’d known he was talking about all of them. In no time, they had the wading pools relatively evenly dispersed through the hall.

That task completed, Harry began to walk through the hall, and while he’d expected this, it was still disappointing that practically everyone was paired with someone they knew from their own house. So, he walked through the crowd of students, introducing himself and learning their names before re-pairing them with a student from a different house.

Harry truly believed that encouraging house unity was important, not just for the war effort, but for the overall environment at Hogwarts. He thought that starting small with mixing pairs at a club was a small way to begin to encourage that.

While he’d been going around correcting the pairs, nobody had started actually practicing the spell. Which Harry supposed made sense, since they would be interrupted once Harry came by to re-pair them. But once he’d already spoken to a pair, there was still little reason to not get started on the spell. Despite this, the only motion in the room was the sound of people getting to know their partner- or, in many cases, as Harry had to acknowledge, talking to their nearby friends and ignoring their partner.

He scooped a ball out of a nearby wading pool and lobbed it at Ron, who was somewhat facing him as he got to know the Hufflepuff that Harry had paired him with. Ron saw it coming, and was just barely able to cast the shield in time to deflect it. His visualization must have been slightly off because the ball bounced off away from Harry, but he’d otherwise done an excellent job.

This was enough to start a cascade of students grabbing beach balls and tossing them at their partners. The Great Hall was soon full of the sound of shields being cast and raucous laughter as people inevitably got hit with deflected beach balls. Harry smiled briefly at the sound before beginning to move through the room, checking people’s techniques and giving mild corrections.

He wandered over to where Neville was paired with a fifth-year Ravenclaw Harry thought was named Polly and Eli was paired with Blaise Zabini.

The first thing Harry noticed was that Neville almost had his shield perfectly conjured, he just needed to exaggerate one of the wand movements a little more and he’d be there. He moved to stand next to Neville and waited till Polly tossed the beach ball at him. As Harry had expected, the ball failed to bounce off the shield like it would if it was solid and instead was deflected downwards, colliding with Neville’s legs instead of his face.

Polly had grabbed another beach ball, but Harry put his hand up to stop her. “One moment, please,” he said politely, and Polly shrugged and started tossing the ball to herself.

Turning back to Neville, Harry saw that he was thoughtfully practicing the wand movements.

“I know that I’m pronouncing it right, and I’m almost certain my visualization is good because the shield appears exactly how I’m seeing it, so I think that the problem must be with my wand movements. Only, I can’t figure out what’s wrong,” Neville said, still sounding slightly detached from his surroundings and utterly focused on watching his wand.

Harry joined him in watching his wand movements, just to be sure that his theory was right. After another iteration, Harry said, “I think I know what your problem is.” He lifted his own wand and started the specific motion Neville was having trouble with.

“See this part? Watch how I really exaggerate the wrist movement,” Harry said as he repeated the motion a couple times.

Neville was watching him closely and after a couple repetitions, copied Harry.

Harry watched his motion again and this time he seemed to have it. “Do you want to give it another shot?” he asked Neville. He nodded, so Harry said, “Hey Polly, can we get a beach ball toss?”

Polly caught the ball she’d been bouncing on her forehead. “Sure,” she said, before she lobbed it at Neville.

Neville was ready though, and cast the spell again. This time, the ball bounced right back to Polly, who caught the ball, only to set it down to give Neville a brief round of applause. Harry smiled and joined in for a moment.

“Good job, Neville,” Harry said.

Neville shifted slightly and said, “It was really easy once you showed me what I was doing wrong.”

Harry had noticed that Eli was just standing around, so he smiled and nodded at Neville, then moved over to Eli to see what was up.

“Have you both managed the shield?” Harry asked as he approached them.

Eli started slightly at this, then said, “Yes.”

Harry thought he still sounded distracted, but since Blaise had also said “Yes,” there wasn’t much he could do at the moment. He moved on to a nearby clump of third years who all seemed to be struggling, and began to patiently demonstrate the wand movements. He could always ask Eli if he was alright after the meeting.