Defense Against the Unknown.

Disclaimer: I do not own Harry Potter. J.K. Rowling does.

Chapter 2

Harry sighed as he strode down the hallway of the second floor. Classes were going to begin in half an hour and he had yet to find his classroom. He had once again forgotten that classrooms changed positions each year. After a simple Point Me spell, he found his way. Running his hand through his already messy hair, he opened the large wooden door of the DADA classroom.

The room was a mess after the summer holiday. Feeling too lazy to take out his wand, Harry simply waved his hand over the room. 'It's not like there's anyone watching me perform wand less magic anyway.' The dust banished itself and the chairs and the desks immediately straightened themselves. The board wiped itself clean and the extra textbooks piled themselves neatly on a table beside his desk. He placed his lesson plan for the day on his desk. He turned around to study his room.

'It's a large room, but I would have to enlarge it once we start with practicing the spells.'

Hearing the excited first years make their way down the halls and to his class Harry quickly decided to surprise the class.

'It would be easy to see who the early birds are and who the latecomers are.' He swept his arm over himself and distinctly felt himself change into his amphibian form. Harry slithered up the board until he had a good vantage point. Relaxing immediately, he stopped moving completely. Just in time too, seeing that the door opened and three happy first years came in.

Their expression fell once they found the classroom empty.

"Are you sure that Professor Potter comes to class 15 minutes early?"

"I'm sure. Mother said that he was meticulous with his timing. You also heard Dumbledore mention that he came exactly 15 minutes early."

"Well I hope he gets here soon, my feet are tired from that long walk," a snotty female voice whined in the background.

Harry mentally sighed. If the kid is already tired then I'm sorely disappointed. I expected much more, ah well. Once I'm through with them, a jog around the castle will seem like nothing.'

"There's still 3 more minutes until 15 minutes before class, let's grab a seat at the front."

"That sounded really weird coming from you. I thought you hated school and class," a voice that distinctly sounded like a younger version of Crabbe said.

"Of course he does, but he's simply too happy with meeting the Harry Potter," it was the same disdainful female voice that spoke earlier.

Remaining completely still, Harry glanced down and noticed that green and silver was on their robes. 'Just great, I've got to deal with snotty nosed Slytherin's first thing in the morning. Why couldn't I have the Ravenclaws, or even the Hufflepuffs? They are docile enough. Too bad there are too many first years this year that we have separate classes for each house instead of the usual combination of two houses.'

"Hey, is that a snake up there on the board?"

Years of training kept Harry very still. Though he wasn't concerned that he was spotted, it was better to be left alone. Better safe than sorry he decided.

"Yea well, it is fitting don't you think? We are Slytherin after all."

"Who cares about the snake. It might just be a stone figure. Professor Potter still hasn't arrived yet and it's past the fifteen minute mark."

The three students remained quiet as they continued to wait. When the first warning bell rang, Harry could see that they were getting impatient. A few more students walked in, chatting happily. They took seats in the center. By now, the trio of students that came in first were getting irritated. A scowl was on the female's face. She was obviously annoyed with her chattering house mates. The males were tapping their foot impatiently.

The final warning bell rang signaling that there were only five minutes left until class began. Students came pouring in. Harry felt the atmosphere immediately thicken with tension. These students were impassive and walked with the dignity of royalty. 'Their parents must be one's that still think that pureblood is more important.'

The happy chattering from the second group became a lot quieter. They had obviously detected the hostility directed at them. The air held a certain amount of arrogance and animosity as some of the students glared at each other. 'The second group must be muggles.'

At that precise moment, Joshua and Daniel entered the classroom. It became quiet once more as the eyes of all the students followed them. They sat down quietly and took out their books.

Daniel glanced around the class studying his surroundings. He noticed the black snake up on the board. His eyes narrowed and suddenly comprehension dawned on him. He looked straight into the eyes of the snake and smirked.

'It looks like both Daniel and Joshua has noticed.'

If it were possible, it seemed as though the snake was smirking right back at them.

The bell rang and classes had started. Harry was happy to note that all his students arrived early. Murmuring began once again, although this time it was merely speculation upon his family. In the eyes of the students, they seemed to exude a powerful and mysterious aura; an aura that was very similar to their fathers. Harry continued to observe his class and their behavior.

Suddenly the snotty girl yelled out in frustration, "Where in this bloody world is Professor Potter? I thought he was supposed to be a decent teacher but he shows up late on the first day of class."

"Hey, don't insult Professor Potter! Perhaps he was just getting coffee! It was a long night yesterday," one of the muggle-born Slytherin's defended him.

'Surprising seeing how hard it is for muggles to be sorted into a pureblood loving house.'

"Coffee? What the hell is that? You filthy muggle-born wouldn't know the first thing about being diligent."

"What do you mean by filthy muggle? You're a human yourself!" the voice was rising in anger.

The rest of the class was extremely quiet and the tension was thick in the room. Everyone was paying attention to the argument, except for Daniel and Joshua. They kept facing forward and kept eye contact with the black snake.

Harry sighed and started to slither down the board and towards the arguing pair. 'Better stop it before it really begins.' Harry kept his eye on the students but none of them noticed him. They were all listening to the girl rant.

"Of course you wouldn't understand. How can I forget? Father told me about you," she snarled viciously.

Harry narrowed his eyes, making them look like tiny slits in his form. He knew what she was about to say next, and he did not like it one bit. 'It seems as though Dan and Josh knows too seeing how they have stiffened in their seats.'

"You are stinking mud-," she stopped speaking feeling a wand pointed directly at her skull.

The class gasped as they noticed their Professor standing in the middle of the class. They were wondering how he got there. It was common knowledge that apparating was not allowed within Hogwarts so that meant he was here all along!

"I wouldn't finish that word if I were you," Harry said in an icy tone. Everyone recognized his contained fury within those words.

The Slytherin gulped and turned around to face her professor. Gathering her courage she spat, "Why should I when it's true? What kind of professor are you for showing up late? You are supposed to be the Harry Potter, the genius prodigy who defeated the dark lord. You're nothing more than a man basking in his former glory."

The eyes of the class widened. They all wondered how their professor would react. The younger Potter narrowed his eyes in a dangerous way. Harry looked impassively at the arrogant girl before him. It was time to bring her down a few notches.

"You and your parents have obviously learned nothing in the last war. Blood does not matter. Have you not heard that the one of the greatest hero's was a muggle born witch? She was the brightest witch of her generation. Even the Draco Malfoy, also known as one of the Slytherin prince's respected her. She is the head healer at the hospital your mother works in," Harry said this in a very cold tone making the girl nervous. 'She is obviously Parkinson's daughter,' Harry thought.

"Who says I wasn't here?" Harry asked raising his eyebrows. He cut in before anyone could say a word. "I was here since you and your friends came in. I even heard you complaining about you sore feet from the long walk down the hall."

The class snickered at Parkinson's obvious humiliation. She was flushed with embarrassment and anger, "But how?" It was a rhetorical question seeing that she knew right away. She quickly glanced at the board to confirm her suspicion. She pointed a finger at him, "You were the snake up there!" Her eyes widened in horror. She remembered her behavior before this and all the things she had said. She realized she was in a lot of trouble.

Harry nodded his head in confirmation, "Yes I was.
Some of the students seemed eager at the prospect of him teaching them now. "I am not a man who basks in his glory Ms. Parkinson. I shall tell you that I've always hated it, just to ensure that you got your facts straight. Now please take a seat."

Harry strode to the front of the class and faced them, "I am really disappointed with your behavior. I expected more from the house I resided in. 25 points will be deducted."

Even though his house lost points, Daniel looked very smug at the thought that his father had gained the respect of all the first year Slytherin's. 'Way to go dad!'

"Before we begin, let me make myself clear. I tolerate many things, but I do not tolerate that word." Before anyone could interrupt him to ask what the word was, " For those who don't know what that word is, keep it that way. For those who know what I'm talking about, keep that in mind." Harry pointedly looked at Parkinson.

"Okay, now open up your books to Chapter 1. We will be learning the theory of the Finite Incantatem. In my classes, you first learn the theory. The next day we will practice it. You do not need your books for that day. I don't care if you already know it, practice makes perfect and I need you to be able to pull off all the spells I teach you without much effort. Do I make myself clear? Are there any questions?"

All the students were listening with rapt attention. Since no hands rose he continued, "Good, can anyone tell me what the purpose of the Finite Incantatem is?"

A few students raised their hands. However, Harry saw a shy witch in the center of the class that reminded him strongly of Neville when he first met him. Deciding that she needed to break out of that oppressive shell, Harry picked her. "How about you miss?"

"Brown. Anne Brown," the girl squeaked. Her face showed that she was mortified that she was picked to answer a question.

Harry smiled encouragingly at her. "The Finite Incantatem is a spell that negates the effects of many spells."

"Correct, Ms. Brown." Anne let out an audible sigh of relief.

"The Finite Incantatem has the ability to cancel out many other spells," Harry continued with his lecture. "Now is there anyone who knows how to perform the spell?" Glancing around, only a few tentative hands rose excluding those of Joshua and Daniel. Harry sighed, 'We have a lot to do.'

"Alright then, since the majority of the class does not know how to perform the spell, let's have a demonstration. Are there any volunteers?"

Everyone simply stared, none being brave enough to raise their hands. Harry sighed again, 'Time to provoke them then.' "Alright, since you Slytherin's are apparently cowards, I will-"

At the word cowards, much the class made sounds of indignant fury. However the most furious of them all was one of the muggles.

"We're no cowards! I volunteer for this demonstration!"

Harry arched his eyebrow, "And what might your name be?"

"Greg Smith, Professor Potter." The other students looked at Greg with puzzlement.

'Surprising to see that out of all these prideful Slytherin's, it is the muggle that they despise that defends their honor,' Harry thought.

"Thank you Mr. Smith. Would you please come up to the front of the class?" As Greg stomped his way to the front, all the while trying to maintain his cool, Harry called upon the class again. "Now, would one of the students who believe that they can do the spell volunteer?"

Once again, no one raised their hand. Blinking a couple of times, Harry sighed. 'This is quite unbelievable…' "Alright then, Joshua please come up. I know you can do this."

Giving Harry a weary look, Joshua got up from his seat and headed toward the front of the class. Pulling out his wand from his sleeves in one swift movement, he gave Harry a nod to indicate that he was ready.

"Alright class, I will now cast a fully body bind on Mr. Smith and Mr. Malfoy will demonstrate how to negate it. Watch carefully and pay attention. 'Petrificus Totallus' ".

Greg stiffened and his eyes widened comically. With a dull thud, he fell to the floor. Some of the students winced at the imaginary pain that one would receive when they fell face first to the ground unprotected.

Joshua pointed his wand at Greg and softly whispered, "Finite Incantatem," His words were barely audible and the lack of concentration may have indicated that nothing had happened. However Greg came back to life, flailing his arms wildly.

The class of first years stared at the ease in which Joshua did the spell. Harry coughed intentionally to clear the class out of its stupor. "That was well done, you two may go back to your seats. Now class, you've been given a perfect demonstration and I expect you to practice the wand work and pronunciation tonight. Tomorrow, everyone will need a partner. For those unable to cast the spell correctly, you're going to have to suffer through whatever unfortunate curse I happen to choose. On this note, choose your partner well." Harry chuckled as the class gulped in nervousness.

They had seen the wicked predatory gleam in the Professor's eye and they were suddenly struck with unease.

"You can use the rest of the class to look over the notes pick a partner and ask me questions," the Professor continued.

The class exploded into a fury of chatter as students desperately tried to find a competent partner. 'They are all over the place,' Harry thought.

Joshua and Daniel looked at one another and nodded. They knew what to expect and what to do. They were partners and with that said, that was how the first period of the first day ended.

Lunch time in the Great Hall was a huge event as the students chattered nonstop. There were rumors of the new DADA professor floating about that had many of the other staff quite puzzled. Dumbledore simply kept an amused glint in his eye.

According to the Slytherin's their professor greeted them as a snake but based upon the chattering of the Hufflepuff's, he was an intelligent badger. Ravenclaw on the other hand insisted that he flew in as a raven. However, that wasn't the most outrageous form he had taken. Apparently, Professor Potter scared the living daylights out of the Gryffindor's when he gave the fourth years a roar as a welcome.

"He was a friggin' lion I tell you!" a fourth year Gryffindor babbled excitedly.

"No, he was a raven with magnificent wings," yelled a Ravenclaw from her table.

The Great Hall erupted into yells as students argued over what the best form Professor Potter had taken. The staff simply ignored this chaos as they knew that this was simply the beginning. Dumbledore was simply chuckling in his chair, amused by this whole event. 'Ah Harry! Simply wonderful! It seems as though you've brought back the excitement that has left since your days at Hogwarts.'

"Again!" Harry's distinctive voice punctuated the room full of exhausted children. With a wave of his wand, half the first year Slytherins were once again petrified. As one, the class chanted 'Finite Incantatem!' while moving their wands in the correct motion. Harry gave a sigh of relief. At long last, after three days of practicing this spell, the students have finally got it down decently.

The other half of the class got up with a groan, rubbing their sore and pained muscles. Most of the other students were covered in sweat from their exertions. This first day was the most painful experience that the first years would remember for quite some time. Many students believing that Professor Potter would be easy going since it was only the first week of classes were severely mistaken. Since they had hardly practiced the spell or the wand movements, many students had to suffer the humiliation of the spell cast on them by the professor.

Harry staying true to his words let those students wander the school with neon pink hair, fat lips, buck teeth and a mane of a beast for the rest of the day. Of course if you had a bad partner you couldn't help it, so he freed those that could actually perform the spell but let those who couldn't suffer from the effects of his spells. These were only minor little spells that would wear off when the day ended, and he used these as a simple warning.

Those that still didn't understand or practice suffered much more painful curses. Some had to walk around all day with legs made of jelly, some didn't have their sight, or sense of smell and touch, some even had wings as arms and hairy legs. But they all soon learned their lesson soon enough. It was quite an amusing sight these past two days though. The other professor's didn't interfere with Harry's training methods because it was actually helping the students to become more disciplined.

"Alright! That's enough. I'm quite happy with the results of today's training. I will therefore not give you a paper to write tonight. However, I'd like all of you to start reading Chapter 2, the stunning spells."

The class was quite happy that they had finally finished with this torturous training. Theory was definitely much better they thought. Some students even preferred to write essays than continue, but this was a once in a lifetime opportunity. They were being trained by Harry Potter.

Those who thought that the tough training was finally over would probably faint from what would come next. So much like this, the next two weeks passed in a very similar manner. Theory and then practical training. It was strenuous training but the students were getting used to it and they were beginning to feel the effects of this training. They felt fit and ready to face anything.

'Oh how naïve they are…' Harry mused as he glanced at them practicing the 'Stupefy' spell. They have finally been able to hit moving targets and were improving but they still had a ways to go.

"Time for a break!" Harry shouted.

As the class sat down or did stretches to cool down, Anne Brown surrounded by her group of friends put up her hand shyly. "Professor Potter, we were wondering if you could tell us the story of your childhood and how you defeated the dark lord. It's been such a mystery and everyone is dying to know."

"Ahh, I guess that wouldn't hurt. " Even Daniel and Joshua looked up with interest at this. "So how should I begin…?"