Disclaimer: I don't own Harry Potter or Red Vs Blue. Harry Potter is the property of J.K Rowling and RvB is the property of the good folks down at Roosterteeth.

Author's Note: This is a perfect example of why you shouldn't watch Red Vs Blue episodes straight when you're halfway through reading a Harry Potter book. Results may vary. Please review. Also, if the characters are out-of-character, than it's simply because the only reason I'm writing this in the first place is because my brain is high on caffeine.

Defence Against the Blue Arts

It was the beginning of Harry's fourth year of Hogwarts and all was well. For now. Nearly everyone in the school knew something bad was going to happen. The only ones who didn't know were the first years and nobody told them. It was best to let them keep their innocence for now.

The simple truth was that something bad had happened at Hogwarts every year for four years now. And they almost always involved the Defence Against the Dark Arts teacher. As a result of this, the school went through Defence teachers like other schools went through PE equipment.

Understandably, there were very few people who were now willing to sign up for the job. In fact, only one person showed up for the job interviews. Dumbledore had been so desperate he had given the job to the man without asking him about previous experience, magical ability or even given him a basic aptitude test.

But despite his worst fears, the new teacher had seemed to integrate with the other teachers fairly well. He was a bit…odd in some places. He always insisted in wearing some sort of strange bright red armour wherever he went. He often went into violent incomprehensible rages and formulated even more incomprehensible teaching plans. To top it off, he continually referred to Dumbledore as 'Red Command'.

But despite this, he had not been the weirdest teacher that Hogwarts had had in its illustrious history. He had also been willing to work for no money whatsoever. When Dumbledore mentioned this to him the new teacher had told him that he still had over five years of wages from his old employers who had so far neglected to pay him. He had then revealed to Dumbledore his 'genius' scheme to get the money. Like all of his plans, it made little sense and seemed completely detached from reality. It seemed to involve bloodshed, high-powered laser cannons, more bloodshed, Spanish robots, even more bloodshed and the repeated maiming of somebody called 'Grif'.

The true test however would come in a few days time as the students came to Hogwarts and the new teacher started his Defence curriculum. When asked whether had had experience fighting the forces of darkness, the man (Dumbledore couldn't recall his name at the moment…started with an S) said that he had spent over five years apparently, in his own words, "locked in epic combat with those damn dirty Blues!"

Harry, Ron and Hermione were walking down one of the schools many corridors. Their new teacher had been absent from the welcoming banquet so rumours had been running rife throughout the Hogwarts student body on who or what the teacher was. Since the last teacher had been a werewolf, one student had said, with out luck this one's probably a vampire.

All Harry knew was that the new DADA classroom was now down deep in Hogwarts dungeons for some reason. As they walked the down the corridor past the Potions classrooms they picked up others who were also heading towards the new classroom for their first Defence Against the Dark Arts class of the year.

There was Seamus and Dean. Neville Longbottom. And of course, there was always Draco with his gang of Slytherin cronies.

They could hear him talking and his cronies agreeing to whatever he said.

"This teacher can't be worse than our last teacher," he sniggered. "Can you believe that we had a werewolf teaching us? Well it won't happen again. My father has a lot of influence," he continued, as if he hadn't already reminded everybody of this fact at least once every five minutes. "And he's made sure that the next teacher was human, not just somebody who probably spends his time fetching sticks!'

His cronies laughed along with him.

For a moment, Harry felt like pulling out his wand and jinxing Malfoy for what he had said about Lupin. It wasn't just that. Draco had done nothing but mouth off Lupin and spread rumours about him ever since they found out Lupin's…condition.

They reached the new classroom. The door was unlocked so the students filed in and sat down at their desks. A minute passed. Then another. Harry stirred restlessly. Where was their new teacher? Several more minutes passed before Draco got up.

"You can all stay here if you want," he sneered. "But I have better things to do."

He was almost out the door when one of the cupboards burst open and a blur of red slammed into Draco and knocked him off his feet and onto the floor. Harry's eyes almost bulged out of their sockets.

Standing over Draco's prone form was a tall figure wearing bright royal red armour. The armour wasn't the kind of armour that the suits of armour around Hogwarts were though. It was a complicated system of red metal plates stretched over some sort of black undersuit. A red helmet that had a large golden faceplate covered the head.

Held in the mans hands was a strange black device that a good deal of students didn't recognise. Harry, Hermione and the few others who had had sufficient exposure to Muggles knew what it was however, some sort of shotgun.

"Impossible," Hermione muttered under her breath. "Technology can't possibly work in Hogwarts."

The armoured man spoke in a loud voice that seemed to be a controlled shout. Harry recognised it as a Southern American accent.

'Now son! If that had been one of them dirty Blues hiding in that closet, where would you be now? I'll tell you! They would've dragged you away to their base to perform their no doubt depraved and diabolical brainwashing techniques on you! You must maintain an air of constant vigilance!"

He extended a hand to a clearly shaken Draco.

"You want a hand?"

Draco slowly extended his own hand towards the stranger's hand only to have it seized in a crushing grip. Draco was pulled up into the air and slammed into a wall.

"You fail again! You're almost as bad as Grif! Almost! I'm no man of science but I am fairly sure that for someone else to be as bad as Grif would involve some sort of bending of the laws of time and space themselves! Now, what if I had been a Blue in disguise? BAM!"

To re-enforce his last words he fired his shotgun straight over Draco's head, gouging a huge hole in the stonework. Draco ducked with a strangled sounding yelp. The rest of the class was still sitting at their desks, gaping with open mouths. The sheer spontaneity of what had just happened meant that none of them had even thought of bringing their wands to bear on the intruder.

Draco was grabbed around the throat.

"Now," the man said in a slightly more kindly tone, "What have you learned from this?"

You could almost see Draco's thoughts as they attempted to move towards his main goal, his own survival against this crimson-clad madman.

'That…" he wheezed as his windpipe was constricted. "That I can never trust anyone..?"

"Wrong!" the hand squeezed harder. "You can always trust me! I'm your Sergeant! To not trust me would be insubordination!"

"But…but." Draco choked his words out. "You just said before that you could've been someone in disguise..'

His words were cut off as the person shook him like a rag doll. The mans voice lowered into an even more dangerous tone.

"That's getting very close to insubordination against a superior officer. You wouldn't be doing that would you?"

"Er…no! Of course not!"

"Of course not what?"

"Of course not…Sir?"

"Good! Now, what have you learned from this?"

"That…you are always right?"

Draco said the only thing that would seem to save him from death via asphyxiation. Fortunately, his attacker seemed to agree with him. The armoured hand released his throat and Draco dropped to the ground, gasping for air.

"Excellent ass-kissing there, boy! Maybe you're a Simmons, not a Grif!"

Draco breathed a sigh of relief, although he could tell that any slip-ups would have him demoted back to 'Grif' status. He didn't know who 'Grif' was but he was sure it was bad.

At this point one of the students had come to his senses. Drawing his wand he yelled 'Stupefy!' as a red beam of light projected itself at Draco's attacker.

It bounced off. The stun beam seemed to hit a crackling energy field and was deflected into the ceiling. The man turned to look at the student.

"Aha! I knew it! A Blue spy!"

He unslung his shotgun and all of the students immediately ducked beneath their desks as a series of blasts ripped apart everything next to the offending student in a display of horrendous aim.

When the dust cleared, it showed the student lying on the ground among the shattered pieces of wood that had once been his desk. It would later be found that he had several jagged pieces of wooden shrapnel in his arms and legs and a case of Post Traumatic Stress Disorder.

The shotgun barrel levelled itself at the other students.

'Any other objections that you damn Blue spies would like to raise? I know there are more of you in here. Maybe it's you, or you! OR YOU!"

He accompanied the last word with a violent gesture at Neville Longbottom, causing him to squeal in terror.

The man holstered his gun, sat down at the seat behind the teacher's desk and spoke again in a (slightly) calmer tone.

"Hello children. I am Sarge and I am your new Defence Against the Dark Arts teacher. Any questions?"

These last words were directed once more at Neville who was shivering in what to Sarge looked almost like a Blue shiver. This kid was one to watch. Probably another Blue spy. They're everywhere!

Neville shook his head violently.

"No Professor Sarge."

"Its just Sarge! I don't need no fancy title to back up my authority! I am authority!"

"B-but…all of our other teachers are called Profe-"

"What's this? Insubordination!?"

With a roar, Sarge pushed over his own desk and ran full-pelt straight at Neville with his fists held high. Neville gave a strangled scream before fainting, right before Sarge got to him.

A detached part of Harry's mind noted that that was two students unconscious, not counting Malfoy as he had rejoined his cronies, pale faced and shaking. He couldn't help but wonder how high that number would rise.

Sarge stood in front of a blackboard that seemed to be covered with meaningless and over-complicated squiggles.

"Now, Red Command has clearly stated that I must teach you how to defend yourselves from evil and foul creatures of darkness! I have decided, in my own awesome wisdom, to teach you how to combat the most foul and evil beings of all…The Blues!"

Harry was not the only one wondering just what the hell a 'Blue' was, as Sarge seemed to be talking about them all the time.

"The first step is how to recognise a Blue! Blues are cunning creatures and can no doubt take any number of diabolical disguises! But mostly, they look like a man in crazy blue armour. Yes what is it?"

Hermione had raised her hand, her inquiring spirit obviously not even dampened by this most bizarre of all teachers.

"So, these…'Blues' look just like you but blue?"

"Of course not! There are other differences! Underneath my armour, I'm a handsome devil in the prime of his life! Under a Blues helmet however…well, let's just say that they're the ugliest things I have ever laid eyes on aside from Grif!"

Sarge continues his explanation.

"There is one sure-fire way to tell is somebody is a blue!"

Hermione interrupted again.

"That they're blue?"

"No, not that dirt bag! You have just proven your own ignorance! The best way to tell a Blue apart is that they're always scheming or conniving! Sometimes they're doing both at the same time! I call that 'schonniving'."

The lesion continued much along those sorts of lines, with Sarge talking at great length and incomprehensibility about the 'diabolical Blues'. One memorable part was when he had told them that the best way to kill a Blue was to:

"…Take him down with your bare hands! Sure, you can use guns or those sissy little sticks of yours but there's no honour in that! You have to get him in close combat, so he knows that you're the one beating him to death!"

Sarge then moved on to screaming out propaganda chants for something called 'The Red Army' with Draco out next to him agreeing with everything he said. The students had to roar the chants back to him before he was satisfied.

And then Sarge ordered the students to get some 'combat experience'. This had consisted of the students running around and hiding in the large classroom while their teacher started randomly throwing grenades.

"If you can dodge a grenade, you can dodge a Blue! Not that you should dodge them of course! You have to meet the Blues head on! With violence!"

Fortunately, no students had sustained any serious injury, although quite a few more had been rendered unconsciousness by some way or another. Draco had been able to avoid the worst of it by taking up on his new position as Sarge's chief lackey or as Sarge called it, 'Simmons impersonator'.

By the time Sarge had got to the point where the students were furiously running laps around the classroom as Sarge shouted insults at them, there was less than half of the class left.

Ron had had enough.

He stopped running to catch his breath. Sarge almost immediately appeared right next to him, causing him to jump in surprise.

"Why aren't you running soldier!?"

"I'm not a soldier! I'm sick of running and this has nothing to do with Defence Against the Dark Arts!"

"Lazy Bluetard!" Sarge yelled directly into his ear. "You don't want to run because your lazy, just like Grif. Well, I know how to deal with you!"

He gestured to Draco, who came forward.

"Malfoy, transform into a motorcycle and destroy Weasley!"

They both looked at him dumbfounded. Draco was the first to speak.

'Wait…what?"

"You heard me! Motor-Malfoy, run Gri- I mean Weasley over!"

They just stood there gaping at them. Sarge's insanity had seemed to have struck new levels.

"Nevermind! I'll get him myself!"

Sarge started forward as Ron gave a high-pitched scream before running to the door. He was intercepted halfway as Sarge tackled him to the ground, pinning him under his heavily armoured bulk. There were several cracking sounds.

Draco spoke up again.

"Uh..sir? I don't think Ron can breathe like that."

"Nonsense! When under stress, the human body is perfectly capable of producing it's own oxygen by photosynthesising the suns rays!"

Despite what he said, Sarge got him up anyway and looked at the somewhat crushed form of Ron.

"You people can heal broken bones right?"

"Yes sir."

"How many of his bones should I break until they can't?"

"What are you saying?"

" Come on! I don't want him healed! No doubt, if I injure him enough, they will be unable to heal him fully and Grif, I mean Weasley would spend the rest of his days as a twisted freak, loathed by normal society."

He looked at Ron's prone form.

"Not that he isn't already, that is!"

Malfoy put his hand over Ron's chest, trying to feel a pulse or breathing. There were none.

"Sir! I think you've killed him!"

"I have? Excellent! I must have punctured his lungs, the vital part of his body where the food is digested! Of course, all the congratulation can't go to me! Well done Malfoy with your top-notch ass-kissing throughout this lesson! With the proper training, you could even reach Simmons level! I'm awarding 200 points to Slytherin!"

"You are?"

"Correct! I'm also giving Gryffindor 500 points!'

Draco's face fell.

"But why sir?"

"Because their banner has the greatest of all colours! Red! And they also have the lion, most noble of all sea creatures! In fact, I'm awarding even more points to Gryffindor!"

Malfoy didn't reply. He was too busy thinking of a way to somehow repaint the Slytherin banner red. With Sarge as a teacher, it would almost certainly win it for them!

Sarge watched as what was left of the class ran laps around the classroom. All he needed now was to get Lopez over to this universe somehow and build him a huge holographic training chamber.

As stated at the beginning, something bad always happened with the Defence teacher. Instead this time, it wasn't happening to the Defence teacher. It was happening to anyone who was in a five hundred metre radius of the Defence teacher.

High up in Hogwarts tower, after a door guarded by a secret password was a luxuriant office, the Headmasters office. From the office sounded a disbelieving shout.

"He did WHAT?"