Harry turned as he left dinner in the Great Hall and found several team members of the Chudley Cannons setting up their sleeping bags along the wall of the Entrance Hall for the night. "Yeah?" Harry asked. He hadn't spoken to any of them yet, though Axle and Draco had informed him that Ron made a point of pestering them whenever he could with questions about maneuvers, and had several autographs from each team member. ‘They know my name Harry. They know who I am!' Ron had told him the day after he'd returned. Harry was too busy bouncing back and forth between numb and anxious to be too star struck however.

"Can you teach us to cast a strong patronus like fyou did the students?"

"Erm-"

"Go on Potter, you got time for us yeah?" another teammate said. Harry knew he was a Chaser but couldn't remember his name. He wasn't as up to date with the Cannons as he was with the Falmouth Falcons.

"Right now?" Harry asked for confirmation. He didn't have anywhere to be for a few more minutes when after school classes would start.

"Yeah," the team's Keeper said.

Dumbledore passed Harry on his way up the stairs in the Entrance Hall and winked at him. He supposed he had to now. "Ok," Harry told them.

The Cannons leaned up against the stairway banister or against the walls near their belongings and listened intently as Harry described coming up with an appropriate memory, and no one interrupted him until he was done. They asked questions and practiced casting until two of them had it down and the others had strong wisps coming from their wands.

"What else?" asked Ball, their Seeker. Harry was a bit in awe of him. The Cannon's had one of the best Seekers, and Harry had been happy to enthuse about his moves with Ron in previous years.

"What do you mean?"

"What else you got to teach us?"

"Erm-"

"What about that fancy magic you've been using against Death Eaters?" Ball asked insistently.

"That's Root. I'm not very good at that."

"But you must have something good for defending ourselves."

"What about reinforcing shields?" Harry asked.

"Like the aurors can do?"

"Sure. It takes two to do it though. Better if there's more." Remus had taught him when Harry had been staying with him, and they'd been practicing since they'd returned to the school. Harry had already taught Ron, Neville, and Seamus, and the four of them had been practicing together. Axle, as it turned out, already knew how as it was standard upper year curriculum at Boden.

"Erm-" Harry turned, looking to see if he could spot Ron coming out of the Great Hall from dinner to help him demonstrate, and found that he had a bit of an audience. There were students sitting on the steps leading down into the Entrance Hall listening attentively, some as young as first years, and several upper years were behind him near the front doors leaning against the walls and listening. August was there too in the door to the Great Hall and Harry wondered just how long he'd been teaching the Cannons about Patronuses. Had he missed his first after dinner class?

His eyes found Ron, and he came over to stand with Harry without being asked. "What do you think?" Ron asked. "A blast shield over the front doors?"

Harry nodded, feeling nervous now that he had realized how many people were there listening to him, (how had he not seen them before)?

Ron motioned people near the great oak front doors away impatiently and cast a blast shield.

"The shield isn't big enough to cover the front doors," Harry said to the Cannons, aware that he was really speaking to the entire audience but trying to pretend he wasn't. "No one can cast one that big on their own. If I put my energy into it, it'll grow and get stronger though." Harry turned and cast his energy into Ron's shield. "Professor August," Harry said, "could you throw a mild blasting charm at the door?"

August came to them and cast a hex that made the shield fizzle yellow all over.

"The person who casts the shield initially concentrates on just keeping the shape of the shield... just keeping it up. Everyone else who casts pours their energy into size and strength. When you cast your power into it you have to modulate your magic to fit with the magic that's already there, and you have to work on how much energy you pour in. If you pour a lot of energy in, the shield will be stronger, but you'll tire faster. If you pour too much in all at once, you could burn the shield out, so you have to start with low energy at first when you come into it, modulate your magic, and then you can put more energy into it if you want. Who wants to come up and try it?"

Ball stepped up and cast towards the shield and it immediately fizzled out.

"What happened?" he asked. "I put hardly any power in at all."

"My magic and Harry's magic are different," Ron said. "When they mix they become something else, like mixing potions ingredients. You have to feel what's already there and mix yours in. Your magic has to be part of what we're making, it can't be just yours anymore. Here, try again with just me."

Ball looked irritated, possibly because Ron had already pestered him so much before this, but tried again after Ron cast another shield. The shield blinked in and out for long moments, but eventually held. Harry lifted his wand again and said, "Now just hold on to what you've got, and I'll come in with mine and figure out where I need to modulate my magic to get into the mix." He casted and the shield didn't waver at all.

Ron ended up working with all of the Cannon's team mates at the front door and August and Harry took the rest of the students and split them into two groups. Harry took the younger kids to a corner and August took the older ones to try casting at the entrance to the Great Hall.

Harry sat with the ten kids in his group in a corner and they cast a small easy second year shield around a quill on the floor in the center of their group. Harry held the shield and had each child take turns casting power into it. When everyone was able to do it, he had them practice adding their magic until they were all in.

"This is so cool," a first year Hufflepuff said. "When do we get to learn it on a blasting shield?"

"We'll have to try on a larger sound shield first," Harry said.

"Why?"

"If it's bigger it needs more power. You have to get good at the easy things first."

Harry cast a large sound barrier around their little group and the others began pouring their magic into it. It was so quiet that they didn't hear Ron yelling at them from the outside, though they could see him. Ron gave them a thumbs up and turned back to what he was doing with the Cannons and August's group, who had both put up their own reinforced blast shields now and were firing at each other's shields to see which would hold out longest. Harry turned and put his own blast shield around their group as the younger kids practiced on the sound barrier so they wouldn't be in danger of any stray blasts. When Harry saw the other two groups dispersing, he had the kids lower the sound barrier and told them it was time to go back to their dorms.

"This is so cool," a girl said. "We can have private conversations whenever we want now."

"I could break into your sound shield," a boy told her.

"Yeah? What if Janice helps me reinforce it?"

"I'll get Billy to help me break in then."

"Sounds like good practice," Harry told them, and ushered them off to bed. Ron was talking quietly with the Cannon's Keeper and one of the Beaters and Harry noted August was heading back into the Great Hall. Harry followed as he looked at his watch and realized it was after nine.

"Sir," Harry said, and August turned around. "I'm sorry I disrupted your after school class."

August smiled. "Did the students learn something useful?" he asked.

"Erm, I hope so," Harry said. Remus had said a blasting shield was one of the most important things he could use if there was a firefight.

"Of course they did. Once they had practice with what you taught them, the older students got to practice casting wandlessly. Besides, I wasn't about to stop your class to start mine."

"Sir?"

August smiled and reached forward to tossle Harry's hair slightly. "You're really something Harry, and the more I get to know you, see you interacting with others... teaching them advanced magic that's far beyond what they should be able to do at their skill level, the more foolish I feel about how I treated you at Gemini. Every day a little more foolish," he pondered.

Harry really didn't know what to say to that.

"Twenty people now," August said. "Twenty people can cast a strong patronus; four without a wand. And those are people just from this year, not counting the students you taught in your student club before."

Harry shrugged.

"There's no way a group of eleven and twelve year old should be able to pour magic into shields like that, even sound barriers. The students from Karh maybe, because they study from such a young age, but children from Hogwarts and Boden?" He shook his head and smiled. "That's something."

"I didn't know anyone else was listening in," Harry tried to assure him. "I would never pull people away from their other classes on purpose."

"Maybe you should," August said with a smile, and moved off towards the teacher's lounge behind the Head table. Harry knew August and his wife were staying in a room directly behind it and he was probably turning in for the night.

Harry didn't know what to feel about the impromptu lesson he'd ended up giving the Chudley Cannons plus twenty four students. He felt proud of the younger kids for what they'd accomplished, but uncertain they should be looking to him to be taught at all. He didn't want them following in his footsteps. He didn't want them to be part of the DA and to chase after him into a firefight. They'd end up dead if they did.

Harry's lesson that night was still being talked about the next morning at the staff table and amongst students. Harry heard some younger Ravenclaws at the table behind him complaining at breakfast that they'd missed the lesson, but immediately heard one of the kids he'd been teaching the night before offer to teach his friends.

Two nights later, on his way out of his Healing class after dinner, a group of upper year Ravenclaws including Ernie ambushed him and asked him to teach them any curses and hexes he knew for binding people. Harry told them he only knew a few, and likely the same ones they knew, but they insisted he teach them and soon Harry heard shouts ringing up and down the corridor that, "He's doing it again! Hurry up or we'll miss it!" and, "Harry's doing a lesson!"

It was seven and Harry wondered which classes people were going to skip to learn something he felt totally inadequate teaching. It didn't matter though because he soon had fifteen students around him in the Hospital Wing corridor with Madam Pomfrey supervising (in case of injury). It turned out Harry did know a binding curse they didn't know, and had just assumed they had. He and his friends had checked out and bought so many defense books over the years to teach themselves that he couldn't remember what he'd learned in books or in classes anymore. This time Madam Pomfrey didn't let them go until nearly ten o'clock and had everyone going to their dorms at eight thirty so the few first years there could make their curfew.

Before there was a third instance of people skipping after school classes and keeping Harry from his, Snape- his father pulled him aside. He took him down to his quarters and said he'd be given lunch there as they had things to discuss. Harry wasn't sad about missing lunch in the overcrowded Great Hall, and was glad to have a chance to eat in silence.

"You've been all anyone is talking about the last week," his father said as he handed Harry a plate made by the elves with fish and chips and a handful of celery sticks.

"I'm sorry," Harry said automatically.

"What for?"

He shrugged. If they'd been talking about him he could only imagine the varied reasons why. He'd been doing poorly in Transfiguration and had missed several after school classes for a variety of reasons.

"What are they saying?" Harry asked.

"The talk has been about the lessons you've been giving."

"I didn't mean to. They keep ambushing me in the halls and asking me to tutor them right there."

"Which is what I wanted to talk to you about."

Harry let his shoulders fall. Severus sighed at how fragile the boy's emotions seemed to be, but he knew the reason and so couldn't get upset with him. He would have once said the boy was being dramatic and doing so for attention. Now he knew Harry was just used to being in trouble: fearing the consequences, but being resigned to them. Had the boy believed he was being called down here to be punished?

"The Headmaster approves of the tutoring you have been giving and many of the teachers do not mind that students have missed classes so long as they are learning something valuable."

Harry watched his face closely as he spoke, and Severus wondered if he was trying to read his features, or look into his mind, though he didn't feel any mental intrusion.

"So-" Harry started.

"You may continue, though staff feel it would be beneficial if you set a time and place one day a week on the weekend to host the DA. This would allow you to attend classes yourself and stop students from following you around on the off chance you may decide to host an impromptu class."

Harry thought that was a good idea and a bad idea. He was tired of students following him and being ready to shout at any moment, ‘Harry's teaching!' He was still uncertain about continuing the DA though.

"What are you thinking?"

"I don't want people to follow me."

"Which is why this is a wise idea."

"No- I mean, I don't want them to follow my lead. I don't want them to go into battle and get killed. The Headmaster said it wasn't my choice though, it's theirs."

Severus was silent for several moments and then said, "You are aware that Molly Weasley did not think you should attend Gemini?"

"What?"

"The Headmaster sent you to learn what you could, to fight Voldemort. Molly did not approve."

"I knew she didn't want me to join the Order early but-"

"This is also true. She did not want the Headmaster to divulge any details to you about Voldemort, about the Prophecy, or about the role you must play. What was the result of you having a lack of necessary information?"

"I don't-"

"At the end of your fifth year, did you insert yourself into the fight despite Molly Weasley's insisting you not be told anything?"

"Yes," Harry said, looking down. He still felt guilty about leading his friends into danger and still felt guilty about Sirius' death. Sirius wouldn't be dead if he hadn't run off to the Ministry.

"And if you had had the appropriate information, would that have benefited you?"

"Yes," Harry said, looking up. He wasn't sure where this was going.

"And did you learn something useful at Gemini?"

"A lot of things."

"Things that helped you?"

"Yes."

Severus gave him a meaningful look, but Harry still wasn't picking up on whatever it was the man was trying to tell him.

"Lupin said he told you not to go out, yet you did. And you faced off with Death eaters twice."

"Yeah. Look, that really wasn't his fault. It was my choice. I didn't listen."

Severus gave him another meaningful look, but Harry was tired and cranky and snarked, "If you want me to know something, tell me already."

"Despite that others have told you to stay out of it, you have gone anyway. It was your choice. When you did not have the information you needed to make wise choices, you found yourself and your friends in situations you shouldn't have been in. However, when you were given an opportunity to learn things like tactical planning, Root, and other defensive strategies, you had the tools you needed to defend yourself when you did find yourself in situations where that were necessary."

Severus found that Harry was listening intently, eyes locked with his own. "People will do what they want, and children rarely do as they're told. People have been fighting this war long before you were born, and will continue to do so whether you are here to follow into battle or not. What we have been doing in after school classes is giving students some of the tools they'll need to defend themselves. Death Eaters will not just battle out on the grounds, they'll be in the castle where the students are. So if you have something to teach that might save a life, then do so."

Harry felt deflated. What his father had said made a lot of sense. "I don't know what to teach."

"Many lack common sense. That is a good place to start. Give situations and scenarios to talk and battle through instead of focusing on shields and hexes. A person who can think critically is better equipped with their mind and a jelly legs jinx than a person who knows a thousand curses and shields but doesn't know to stay down and not to run headlong into a firefight."

"Maybe you could help me," Harry said. "And I don't know when to meet."

"I would suggest Saturday after breakfast."

"How do I let people know?"

"I will have the Headmaster make an announcement."

"But tomorrow's Saturday."

"Then we have work to do."

"Can I-"

Severus noted the uncomfortable look on his face.

"What?"

"Ron knows so much of what we did in the DA. He usually helps me. I was wondering if he could come down here and plan with us."

"It is your class. You may do what you wish."

"I don't think I'll get used to that," Harry said. It was strange having people look to him to teach them. Harry had felt that way at first in the DA in fifth year too, but that was more of a club. This was being offered up as a class.

Harry left a few minutes later to go find Ron and made plans with his father to come back to his quarters as soon as he did. Harry found Ron working late in the Newsletter room with Draco, who wasn't supposed to be there at all since their father had banned him from taking part in Newsletter, and they snagged Axle in the corridor on the second floor, and then Ginny in the Entrance Hall. Harry for his part tried to look sorry when he showed up at his father's quarters with the extra students. He wished he and Hermione were on speaking terms, because she was a great planner and was part of the original DA.

"Is this all?" Severus asked when Harry came in with his friends.

"Erm- we're missing Neville and Luna and Hermione."

Severus snorted, called for house elves to bring snacks and tea, and they sat down around the living room to plan what kinds of scenarios to go over. Harry and Severus bounced ideas back and forth so fast the others weren't sure if they should jump in until Ron did and reminded Harry about some of the things they'd faced together. In the end they had a plan and had agreed to split up the students who attended and each take a group. Axle was surprised he was going to be allowed to teach as well, but was as excited as he was nervous about it.

By the time Saturday morning had rolled around, Harry didn't feel nearly as nervous, which was a good thing when he found a hundred students and several staff lingering in the Great Hall after breakfast to wait for the first meeting of the newly formed Defense Association.

Harry, Ron, and Axle went to the teacher's table, which was raised above the rest and Harry did a spell to make his voice carry a little further when he spoke. "We're not covering new spells, shields, or hexes today," he said. "We're going to talk about tactics and how not to get yourself or your friends killed in a firefight."

That statement quickly quieted the room, and Harry found all eyes on him. There were a surprising number of Slytherins here, and Harry wasn't sure if he should be pleased or worried.

"A few members of the DA have been chosen for today to teach you what we have to go over. Because there are so many people, we need to get into small, equal groups to discuss tactical situations. Everyone that's been chosen to teach today has the same information to go over with you. If you want to get something out of this, listen and participate in the discussion."

Ron stepped forward and said, "Get in groups by year. First years over there in the corner, second years by Slytherin table, third years by the back window." Ron went on giving directions until everyone had split up. He'd told the staff that were present to disperse around to various groups without thinking twice about it, and they did as they were asked. Severus ended up working with the seventh years, and Harry went to work with a group of first and second years, who he combined since there were only 12 of them total. The other groups groaned when Harry didn't come to speak with them, but Harry ignored them. Harry noted that some of the kids in his group had worked on shields and barriers with him the week before.

Harry sat down on the floor with his group and motioned for them to do the same and to form a circle.

"What's the number one thing that will get you and your friends killed in a firefight?" He asked, knowing the others teaching that day were asking their groups the same thing.

"The killing curse," a second year girl said boldly.

"A slicing hex," said a first year boy.

"Those will kill you," Harry agreed, "but it's not the number one thing. The one thing that will get you killed is not thinking, not planning, and being reckless."

Harry told them the same thing his father had told him, that they could do a lot more with their brains and a limited number of spells than with complex hexes and no thought to what they were doing at all.

"You're first and second years. The Death Eaters will all be adults or close to it, and they won't think twice about using a killing curse or a slicing hex against you," Harry told them. "And you don't have those curses to fight back with. It's not possible for you to learn some of the hexes and curses the older students know, and it's not possible to teach it all to you in time. We could be attacked tonight, or next week, or next year. We don't know. It could happen right this very minute."

The children in the circle gave a scared look around at each other then, as if the ceiling would collapse right then just because Harry had said it would.

"So what you've got to do is outsmart the people you're fighting, and that is possible. They'll think they have an advantage over you just because they're older and know more than you do with hexes and shields. They'll expect you to have no defense against them at all, but your brain is your biggest defense."

"How Harry?" One of the kids from his earlier shield group asked.

"Let's go over some scenarios you might find yourself in if Death Eaters come into the castle," he told them, "and we'll figure it out together."

The kids looked eager to begin, and Harry paused to listen for a moment to Ron's group, who was already discussing scenarios at the other end of the staff table, arguing about what was the best way to take out two death eaters at once.

"There's been an attack on the castle," Harry said. "It's been going on for a few hours already. You got separated from the Prefect you were with, and it's just you and a group of other first and second years. You're hiding in a classroom in the dungeons."

"But why hide?" asked a boy.

"Because running out into battle with just a few hexes and a shield isn't going to keep you safe. If you and a friend run out into battle with almost nothing to protect you, you and your friend will get killed, and there's a good possibility an older student or staff member might see you and try to protect you and they'll get killed. Do you want to be responsible for that?"

All of the children around him shook their heads.

"So you're hiding in a classroom, just you and some other kids. You're scared, and you hear people start to fight in the hall. What do you do?"

"Uh- put up a shield against the door?"

"Do you know a shield to put against the door?"

"No."

"What can you do to keep them out then?"

"I know a locking spell," said one girl.

"I know two locking spells," said her friend.

"Good," Harry said. "So make sure the door is closed and use both locking spells. What else?"

"It's a classroom, so we can pile some tables up in front of the door," a boy said.

"Yes," Harry said, "what next? What if the person sends two unlocking spells at the door and a blasting spell to get the tables out of the way?"

"What about a rope through the handle?" a boy said. "We could conjure a rope."

"Or use a belt," another boy said, pointing to the belt he was wearing.

"That's a good idea. That would take some doing to get through," Harry told them.

They talked about being prepared with spells already in mind to incapacitate the person, to bind their hands and legs, to gag them so they couldn't speak a spell, and to get their wand away from them.

"What next?" Harry asked. "They got inside, you ganged up on them and bound them and they don't have a wand. What do you do now?"

"Put the barricades back up in front of the door," a girl said.

"What about some traps?" asked her friend. "We could put some spikes or something up, or hang a chair on a rope to swing into them."

"Whatever you can reasonably do," Harry said. "Always be asking yourself though, what next? Think three or four steps ahead. Once you're in that room and you've locked that door, think, "what if they unlock it? After that, what do we do when they're inside? What after that?"

He moved on to a new scenario with them where they were without an older student and were in a corridor in the middle of two people duelling, and after that to scenarios about what to do if they were out on the grounds, where to hide inside and outside the castle, using what they had on hand to fight, and doing what was unexpected. It was lunchtime by the time they finished, and Harry was pleased to see that the other groups had been in such deep discussion that it looked like they didn't want to finish their lesson at all.

"Let's do it again tomorrow," a fifth year boy came up and asked Harry at the end of the meeting, and Harry nodded and went off to collect Neville and Hermione for their next planning session. For the first time in a long time, Harry felt good about their chances to survive this. A hundred and two students and staff had come and learned how to use common sense and strategy. That was almost a third of the people living at the castle. He couldn't wait to come up with something else to save lives for tomorrow.