Disclaimer: I do not own Harry Potter or any of the characters in it. I am merely borrowing J.K Rowling's brilliant characters and backdrop.
Author's Note: This story is cannon up until midway through Harry's fifth year and then diverges.
Severus Snape glided from one potion to the next seamlessly, his bat like robes billowing behind him as he tended to each potion. Chopping an ingredient for one here, stirring another there, and adding an ingredient to a third. Of the eight potions he was currently brewing three were for Poppy, two for the Order of the Phoenix, two for the Dark Lord, and the eighth was a personal project. Severus inhaled deeply catching a whiff of an out of place odor. Turning he caught sight of his experimental brew emitting clouds of purple hued gas into the air. Hurrying over to the potion Severus quickly added a dried nettle neutralizing the smoking potion. Letting out a sigh of relief that there was no longer in any imminent danger Severus returned to a dreamless sleep brew he was working on for Poppy.
As he worked Severus found himself growing nauseated and a pounding headache had began to erupt inside his skull. At first he was able to contribute the ill feelings to stress and exhaustion from being a double agent, dealing with Umbridge, being Hogwarts potions master and professor, and all the work and torture (ahem the dark lord) that came along with such responsibilities. However, once his muscles began to spasm, his body grow numb, and his vision blur Severus grew seriously worried. He had inhaled some of the potent fumes before he had been able to correct the experimental deaging potion he had been working on and he feared his current condition had something do with it. Darkness clouded his vision and before Severus could contemplate his situation any further he dropped off into unconsciousness.
Harry muttered insults under his breath concerning his hated potions professor, Snape, as he scrubbed out cauldrons. The evil bat had assigned him detention for absolutely no reason at all other than to torment him and on the last day before Christmas break too. He supposed it could have been because Ron referred to Snape as a greasy git to Harry in potions class, but first all it had been Ron who said not Harry and secondly there was no way Snape could've heard them. Unfortunately for Harry, Snape apparently had heard with his supersonic hearing and since whenever anything went wrong in potions class Snape blamed Harry the man had taken pleasure in deducting ten points from Gryffindor and assigning Harry detention. Now the hook nosed man wasn't even here to supervise. Harry had debated just leaving considering Snape hadn't left his office in over two hours, but had decided against not wanting to risk leaving Gryffindor pointless. After he had arrived Snape had ordered him to clean an enormous stack of cauldrons and then had gone into his office informing Harry that he had "important work" to do and had not reappeared since.
After scrubbing cauldrons for nearly another hour Harry realized in shock that he had finished with all the cauldrons Snape left for him. Another fifteen minutes passed and now Harry was getting really aggravated.
Annoyed Harry marched up the professor's door and knocked on it loudly. When there was no answer he banged on the door harder. Still nothing.
"Snape," he called, by this point almost hoping that the hook nosed man would whip open the door and start lecturing him about respect. The door didn't open.
Harry tried the door knob and was not surprised to find that it was locked.
"Alohomora," Harry whispered pointing his wand at the door. It swung open and Harry tentatively stepped inside. Snape's office was much as he expected minus any corpses or body parts. The walls were blank and painted a dull grey. The man's desk, however, contrasted sharply to what Harry had expected. Instead of neat stacks of paper he observed papers littered across the desk in what seemed to be an entirely random fashion and various potions books flipped open to various pages scattered across the desk. The only other things in the room were a large bookcase and a potions cabinet. Snape was still nowhere to be found. There was a door on the left side of the office that had been left slightly ajar. Harry curiously made his way towards it. This room was dimmer light than the previous one. There was a long table in the center of the room with eight simmering cauldrons on it. The walls were lined with shelves of potions ingredients most of which Harry couldn't identify. In the back of the room Harry caught sight of a piece of black fabric protruding from what appeared to be a closet. After glancing around to insure Snape hadn't suddenly appeared Harry crept across the cement floor and peaked inside the cupboard. At first all Harry could make out was a dark lump towards the back of the cupboard cluttered with teetering shelves of potion vials.
"Lumos," Harry commanded illuminating the space. As soon as he did Harry immediately wished he hadn't. Huddled in the corner of the cupboard was a small trembling dark haired child wrapped up in Snape's robes.
"No," Harry choked out a million possibilities running through his mind each as ludicrous and appalling as the next. The three most probable being that Snape unknowingly to the rest of them had a kid and was looking him up in cupboard, like the Dursley's had done to Harry, this was some other kid that Snape had kidnapped, or the kid was Snape.
Upon further examination Harry found that the child was injured. There was a small puddle of blood at the boy's feet, his face was bruised, and he cradled his right arm protectively. He also looked like a miniature less hideous version of Snape. His sharp features being less pronounced than they were on the grown man, his nose less hooked, and his ebony hair that still feel in his eyes wasn't greasy. The one feature that mirrored Snape's to absolute perfection was his black tunnel like eyes. This lead Harry to believe that it was either the first or latter possibility.
What did he do? Harry thought panic suddenly surging through in him. Should he try to talk to the child? Dumbledore Harry thought – yes, Dumbledore would know what to do. He could fix this whatever it was. He would go find Dumbledore Harry decided.
Leaving the younger boy in the cupboard Harry nearly ran out of Snape's office and sprinted through the school corridors panting heavily by the time he reached the entrance to Dumbledore's office.
"Lemon drops," Harry gasped praying that Dumbledore hadn't changed the password. The gargoyle jumped aside and Harry stepped onto the staircase. A moment later Harry was standing in Dumbledore's office, but the headmaster was no where to be seen.
Nothing but silence filled the air and Harry cursed under his breath.
"Watch your language young man," one of the paintings lectured. Harry rolled his eyes at the painting not in the mood to be lectured by a two dimensional inanimate object.
"Impertinent Gryffindors," the painting of Phineas Nigellus muttered sending Harry a glare.
"Is the headmaster here?" Harry demanded.
"He's out on business Potter," Phineas replied icily.
"Great, just dandy," Harry growled sarcastically before stomping off out of Dumbledore's office. As he stormed down the hallway he collided with a solid object. Glancing up Harry found himself staring up at the imposing form of Professor McGonagall.
"I'm sorry Professor," Harry apologized hurriedly.
"Where are you going in such a hurry?"
"I was looking for the Headmaster."
"He's out on business, but I am certain I could help with most any problem you have Mr. Potter."
Harry hesitated debating whether or not to tell her about Snape.
"It's kinda complicated," he finally said.
"Well I was at Snape's."
"Professor Snape, Mr. Potter," Professor McGonagall corrected.
"Professor Snape's detention and he hadn't come out of his office for a while, so I went to go look for him. And I uh found this kid in a potions cupboard that looks kind of like Sn- Professor Snape. He was injured pretty bad."
"Show me," McGonagall ordered her lips beginning to form a thin line.
Harry nodded mutely and led the way back to the little boy in Snape's chambers. When he flung open the door the dark haired child was gone.
"Mr. Potter do you find this amusing?"
Before Harry could sputter out an explanation a timid voice from behind them grabbed their attention.
Harry whirled around to see a considerably healthier version of the boy he had previously seen huddled in the closet.
"Severus," Professor McGonagall gasped catching sight of the boy.
The younger boy gave her a confused look.
"Professor why I am at Hogwarts and why are you calling me by my first name?"
"You don't remember?"
"Remember what ma'am?"
"What is the date?" Professor McGonagall asked the younger boy abruptly.
"July 24th 1972," the kid replied the puzzled expression fading as a he suddenly seemed to understand something, "That is not the date is it?"
"No, Severs it is not."
"I was wondering why Potter had green eyes and was suddenly an upper year."
"I believe first we should make a visit to the hospital wing. Mr. Potter informed me that you were injured. After, I shall do my best to explain what has occurred."
"I do not need to see Madame Pomfrey. I am fine," little Snape hissed.
"Professor what is happening? Is he really Snape?" Harry demanded unable to stand the confusion any longer.
"Yes, I'm afraid he is Mr. Potter. Now please return to your dormitory. And Mr. Potter do not speak about this to anyone not even Miss Granger and Mr. Weasley."
"Yes Professor," Harry mumbled turning on his heel and fleeing. Oh, why did it always have to be him?