The Mysterious Professor

by beviris

Summary: In the Marauder's seventh year, the war is breeding, Voldemort is winning, but they still wish a normal year. What they don't know is that this year is going to be anything but normal, especially with the new DADA Professor and his Assistant.

Standard Disclaimer: I don't own anything, except, maybe, the plot line. However, I wasn't the first to think about something like that, so it's not totally mine too. Maybe if pigs could fly I'd be JK Rowling.

A/N: Okay guys, it's my first fanfiction, so please, be fair! I'll change things during the story, not following cannon. Also, I'm editing the story, as I wish its path to be a bit different from the other's. Reviews are really nice, and I hope you enjoy the story as I will probably enjoy writing it!

Prologue: The Marauders Comment

Mr. Moony would like to state that the new DADA teacher is too mysterious for his tastes.

Mr. Padfoot agrees with Mr. Moony and would like to add that the Professor seems to be Mr. Prongs' twin brother.

Mr. Prongs remembers that he seems too young to be a Professor and that he doesn't have a twin brother.

Mr. Wormtail is wishing that dinner arrives quickly.

Mr. Padfoot suggests they try to solve the Professor's mystery

Mr. Prongs likes Mr. Padfoot's suggestion.

Mr. Wormtail agrees with Mr. Prongs and Mr. Padfoot and wishes time would go faster, he is pretty hungry.

Mr. Monny says lets set the plan 'Solve-the-Professor's-mystery' in motion and wants to hit Mr. Wormtail for only thinking about food.

Messrs. Padfoot and Prongs agree with Mr. Moony. Mr. Wormtail agrees only partially.

Chapter 1: The New Professor

James Potter was watching the Sorting, cheering for the new Gryffindors and glancing around the Great Hall, shinny Head Boy badge proudly pinned to his robes. He looked at the Head Table. There was an empty space there, normally reserved for the DADA teacher. He sighed, knowing they wouldn't have this class his seventh year. He certainly wasn't dump and, therefore, knew that was what the absence of a Professor sitting there meant.

Soon, the Sorting ended, something that the Head Boy was quite happy for; after the train ride, he was always starving and this time there wasn't a difference. As always, the Headmaster stood, silencing the Great Hall without much effort. James glanced down to the Gryffindor table and spotted the Head Girl, Lily Evans. She turned and their eyes met, hazel and green, causing her to smile at him. He blushed, but smiled back, happy with their blooming friendship. Since she learned he was Head Boy, she had started to act civilly around him and they were soon talking, mainly about the Head Duties, but it already meant something to him. He looked back at Dumbledore, who had already started his speech.

"The Forbidden Forest is that, forbidden, except when escorted by a professor," his ever twinkling eyes seemed to stop a bit when he looked at the Marauders, "as some would have already guessed, the position of Defense Against the Dark Arts Teacher is unoccupied. Alas, we didn't find a substitute. Until we do, me and the teachers will be dividing the post. Now, I've got one more thing to tell you before we …"

The door to the Great Hall was thrown open and the Professors were all on their feet, wands pointed to the door. The threat of Voldemort got them on high alert and, although the wards weren't disturbed, they still needed to be prepared. Seeing the teacher's position, the students quickly got into position, the younger on the back and the Prefects, Head Boy and Girl on the front. James was sweating slightly, his fingers holding his wand so tightly his knuckles were white, though he didn't show the real extent of his fear. A figure appeared out of nowhere, its black cloak with the hood up giving the impression of a Dementor. The feelings of joy, hope and everything, however, weren't gone, so a Dementor couldn't be, leaving the teachers even more alert. The figure leaned on the wall, seemingly at ease.

"Well, what a reception.." teased it. Its voice seemed to be concealed by a charm, for it was rather deep and almost impossible to identify. It seemed home, even with all the students and staff wands on him. "I was expecting something more joyous, or at least some sign of relief, I mean, this type of receptions are to Moldyshorts and his minions." He sighed. " But that's not the case. So, anybody's gonna ask who I am?" He was a cheeky bastard, James decided, just like Padfoot.

Dumbledore cleared his throat. The wizard didn't seem affected by the Headmaster, which made James pale. There was something almost frightening about this stranger. The Head Boy decided it was the way he behaved, like he was home at Hogwarts; like he'd already been here. "Who are you?" Asked Dumbledore in his calm demeanor. However, the stranger didn't say anything and somehow James knew it was he was smirking under the hood. "I, Albus Dumbledore, Headmaster of Hogwarts School of Witchcraft and Wizardry demand you to tell me who you are." His voice was now clearly demanding, but it didn't seem to affect the stranger much. James mentally cringed, this man was too much like Padfoot and one of them was almost too much to handle, two would be hell on earth.

The stranger leaned off the wall and sighed, again. "Don't need to be so harsh with me, Professor, I'll gladly tell you who I am. I'm Harry, Harry Porter." This seemed to calm the elder a bit. "What are you doing here?" asked the Professor, back in his calm demeanor. James released a mental sigh of relief.

"I was hoping you've already figured out, after all, you are one of the smartest man around, but well..." With a shrug, he pulled his hood off and James' breath hitched in his throat. He was almost his carbon copy, but taller and more, hardened, maybe. There was an aura around him that showed he was a fighter and he had already suffered through much his entire life, and he seemed to be no older than twenty! " I'm here for the Defense Against the Dark Arts teacher position." For the quickest students, this was already obvious. "But you're too young!" shouted one of the Ravenclaws. Typical of them, James knew. This just made the young man smirk.

"Wanna duel to see if I'm capable?" The Ravenclaw just stared at him. "By the way, I'm nineteen." James almost feinted in the middle of the Great Hall, together with half of the staff and pupils. "Mr. Porter, if you are so eager to duel someone, maybe you could try it with Professor Flitwick, what do you think?" Asked Dumbledore. James stood, mouth agape. Flitwick, in spite of his stature, could only be beaten by Dumbledore himself, or Voldemort, he wouldn't be able to beat him, never. The young man looked at the diminutive Charms Professor, his wand already in hand and nodded confidently. Dumbledore quickly prepared everything, by then, the duelers were already in position. "With or without swords, Mr. Porter?" squeaked the Professor. His voice didn't show any fear, though it didn't show confidence or cockiness.

"With." was the only response he got from the other dueler. They bowed and it was on, both duelers going all out, turning into a blur of movement. They all watched, holding their breaths as they moved, throwing curses at each other and battling with the swords. The duel went on for what seemed like forever to James, but was only five minutes. Nobody, except maybe Dumbledore, knew who has won, only discovering when the final move had already been made. The result left James speechless, as Porter had won, not Flitwick like they'd al expected. Porter's sword was on the Professor's neck and the Professor's wand was on the floor. They stood there, shocked, until someone started clapping and they were all clapping too.

"Indeed." Said Professor Dumbledore, silencing everyone. "It seems, at least to me, that we have a temporary Defense Against the Dark Arts teacher. I want you to meet temporary professor Harry Porter." Everyone started clapping once again. Dumbledore quickly restored the Hall to its former arrangement, the House Tables back in place, and went back to the Head Table, not down yet. "Well, this was exciting. Now, I'm sure everybody here is hungry..." Murmurs of agreement filled the Hall, punctuated by a shout of "Bloody right you are!" from Sirius. Lily smacked him in the head, scolding him for his language.

Almost everyone was laughing, the new Professor included. Dumbledore's eyes were twinkling merrily, though it was the only thing that betrayed his amusement. McGonagall was glaring at Sirius, though the effect wasn't as frightening as it was expected, since the corners of her mouth were twitching, almost as if she was trying to fight a smile. Or a smirk, James thought, silently. The Head Boy was also laughing, but a glare from Lily made him shut up.

"So, as Mr. Black so eloquently pointed out, everybody should be starving and I don't want to keep you from eating anymore. Tuck in!" And the feast started, as boisterous as ever, with everyone commenting on the new Professor's duel against Flitwick. The subject of the conversation, James noted, seemed to be talking and laughing with everyone as if he already knew them, one more uncommon thing to add up on the list. And, bloody hell, he wasn't around for an hour!

James was finishing his third serving of Treacle Tart when the Headmaster stood. The desserts disappeared, making him pout, as he still wanted some treacle tart. "We can go to the Kitchens later, mate." reminded Sirius, which was something good that made him stop pouting and look at Dumbledore, who was waiting for everyone's attention. When the Hall was once more silent, he began his last speech of the day. "I think that everyone is satisfied and rather tired. At least I am." There were a few chuckles. James heard Sirius mumble something along the lines of "me not". James smirked, though he agreed whole-heartedly with Sirius. "So, I will not hold you back anymore. Prefects, lead the first years to the Common Room. Head Boy and Girl, please stay behind for a bit. Everyone else, dismissed."

To say that James was confused was an understatement. He looked at Lily, who was just as confused as he was, and shrugged, waiting for the Hall to be empty. Even though he was a curious Marauder, he didn't attempt any type of eavesdropping on the Headmaster's conversation with Porter. He just stared at Lily, but she didn't even acknowledge his stare, as she just sat there looking at both wizards, apparently trying to hear the conversation. He shrugged again and reminded himself of the need to stop doing it. Maybe Lily could find out what was happening and why they were told to stay behind. The Marauders didn't even prank the Welcoming Feast, so he wasn't in trouble. And if it was about a prank, Lily wouldn't be called, for she was never involved with any pranking of his knowledge.

After ten painfully slow minutes, the Professor left and the Headmaster looked back at them, his eyes twinkling. "Calm down, James, Lily. There's nothing wrong with your positions, or anything at all. I'm just going to ask you something." He took a deep breath, his eyes losing some of his twinkle. "I gave you this position because you are two of the most mature students at school. However, I know of your past and your, shall we say, distrust of the other. I need you to put that behind you and work together this year. Take this as a challenge, if you want."

Both nodded, speechless. Dumbledore then excused himself, leaving just the two of them in the empty Great Hall, their jaws on the floor. Five minutes later, Lily shook herself out of the stupor and looked at James, who just shrugged for the third time in twenty minutes. The two of them went to the Gryffindor Head Dormitories making small talk; they really would need to work on their relationship if even Dumbledore asked them to be civil.

"Wow. I thought I was in trouble," Cried James as soon as they were inside the Head Common Room. "It took all my pranking and not being caught experience to not get all pale and sweaty. " he confessed. Lily giggled a little, making him stare dumbly at her. "Wait! Lily Evans, the Resident Gryffindor bookworm, just giggled?!" He asked, still staring at Lily. "Who are you and did you do with Lily Evans?" Lily just giggled, again; James almost fainted.

"I must be dreaming." He got up, retrieved the Marauder's Map from his bag and picked his father's cloak. Lily was still there when he got back, not that it took much time to get the items he needed. "I'm going to the Kitchens to eat some more Treacle Tart. See ya later, Lils." Then he left, one eye on his back to see if she would throw anything at him. Fortunately for the dark-haired man, Lily didn't even have time to scream at him for calling her Lils, as he was already on the Common Room with his friends. She took a pillow, buried her head in it and screamed, frustrated. After venting, she followed his path to meet her friends.

A/N: It's not beta'ed, so any mistakes are mine. I didn't change much, really, just adding some things here and there and correcting some mistakes. It may look like a normal "Harry goes to the past to teach his parents DADA" plot at the beginning, but if I follow the plot I have outlined, it certainly won't be. Reviews make me really happy.

beviris