Disclaimer: I do not own Harry Potter.

A/N: Hello all. I believe I have decided to do a Snape Mentors Harry story but with non-canon pairings. The title is based on a discovery I made regarding a certain Potions class. The speech by Professor McGonagall is from Page 122-123 of the Philospher's Stone. I love the quote about receiving advice. The first time I read it, I was like "WOAH."

Summary: Harry gets sorted into Slytherin. Students and staff are shocked, but none more than his own head of house. Follow Harry as he makes a name for himself and worms his way into even the hardest of hearts. Mixed POV but it will be clear who is who.

INFUSIONS

Chapter 1: Prologue – The Sorting

The Great Hall was abuzz with excitement. September 1st had once again arrived on Hogwarts doorstep, and it was time to welcome another batch of students. At the head table, Professor Severus Snape, guardian of Slytherin House, sat quietly with his thoughts. Unlike his fellow Professors, Severus did not eagerly anticipate the sorting every year. In fact, he dreaded it. So much so that he wished he'd never gotten out of bed. Perhaps, he thought to himself, he could drown his sorrows in Firewhiskey later. This year and the six following were bound to be a nightmare – after all, the son of his worst enemy was arriving at Hogwarts. Little did he know, his life would never be the same again.

SS HP SS HP SS HP

In a small empty chamber beside the Great Hall, the newest students stood nervously, peering at each other when no one thought they could be seen.

Professor McGonagall, a tall witch who wore an emerald green cloak and black pointed hat, began to speak. "Welcome to Hogwarts. The start of term banquet will begin shortly, but before you take your seats in the Great Hall, you will be sorted into your houses. The Sorting is a very important ceremony because while you are here, your house will be something like your family within Hogwarts. You will have classes with the rest of your house, sleep in your house dormitory and spend time in your common room.

"The four houses are called Gryffindor, Hufflepuff, Ravenclaw and Slytherin. Each house has its own noble history and each has produced outstanding witches and wizards. While you are at Hogwarts, your triumphs will earn your house points, while any rule-breaking will lose house points. At the end of the year, the house with the most points will be awarded the House Cup, a great honour. I hope each of you will be a credit to whichever house becomes yours.

"The sorting ceremony will take place in a few moments in front of the rest of the school. I suggest you all smarten yourselves up as much as you can while you are waiting."

Her eyes lingered on a few students, such as Neville Longbottom, who'd managed to somehow get his cloak tucked behind his ear; Ronald Weasley, who had a smudge of dirt on his nose; Hermione Granger, whose hair had taken on the appearance of an electrocuted orangutan; and Harry, who despite his efforts, could not flatten his.

"I shall return when we are ready for you," said Professor McGonagall. "Please wait quietly."

Harry swallowed nervously as she left and turned to his new friend Ron. "How exactly do they sort us?"

Ron shrugged. "Fred said it's some sort of test that hurts a lot, but I don't really think he was serious." Harry's heart gave a horrible jolt, and he tried with all his might to tune out Hermione Granger, who was muttering all the spells she knew and trying to determine which one she might need. Any second now, the Professor would come and lead him home to his doom, where angry and abusive relatives awaited. He hadn't even been this nervous since turning his teacher's hair blue or ending up on the roof.

As he stood, he reflected on the events that had brought him here to this magical school. Letters from 'no one' had arrived at his aunt and uncle's home in Surrey. This led to his uncle becoming madder than he already was – he took desperate steps to stop the 'freakishness' that surrounded his nephew, such as boarding the mail slot, boarding the fire place and eventually running away. They'd ended up in an abandoned hut in the middle of the sea, where waves and wind stormed around them and battered the windows. Then Hagrid, a big man, had arrived with a letter and finally his relatives couldn't stop him from claiming what was his.

They'd visited Diagon Alley and Harry had taken steps to educate himself on the wizarding world, asking plenty of questions and buying as many books as he could. He refused, like always, to step into a situation without thinking of the consequences or being 'unarmed'. The next month was spent reading and trying to stay out of the way. He was extremely grateful that he'd asked Hagrid how to get onto Platform 9 ¾, as it hadn't been terribly obvious. Meeting Hagrid had also brought answers to the silent questions he had about his parents and how they'd died.

Inconspicuously walking through the barrier, Harry decided to put his robes on as soon as he got on the train. He'd done so and done as well as he could to not reveal who he was. Hagrid had revealed to him that his scar made him stand out. Harry just wanted a quiet trip. He'd met Ron Weasley, who was a nice boy with bright red hair and an impressive appetite for food, especially that which was sweet. It felt nice to be free of Petunia, Vernon and Dudley.

A series of gasps behind him recaptured his attention. Around twenty ghosts had just streamed through the back wall. Their pearly white and slightly translucent forms flitted to and fro. They barely glanced at the first years and in fact, seemed to be arguing. A ghost that looked like a fat little monk was heard saying "Forgive and forget, I say, we ought to give him another chance – "

"My dear friar, haven't we given Peeves all the chances he deserves? He gives us all a bad name and he's not really even a ghost, you know – I say, what are you all doing here?" This was said by a ghost in a ruff and tights.

Their musings were interrupted by Professor McGonagall. "Move along now, the ceremony is about to start. Please, form a line." Not wanting to upset the stern looking lady, the students turned their attention from the ghosts filing through the wall to each other and organised themselves as best they could.

Harry felt as though his legs were blocks of ice. He got into line behind a sandy haired boy and with Ron behind him, walked with his peers through the double doors that lead to the Great Hall. Harry had never imagined a place as strange and splendid as this. Thousands of brightly lit candles floated in mid air above four long tables. Each of these were laden with golden plates and goblets that glittered in the light. At the head of the hall was another long table that seated the staff. The long line of first years stopped at this point and faced the other students.

In an effort to avoid the stares, Harry looked up at the ceiling and saw a velvet black sky dotted with stars. Behind him, he heard Hermione Granger whisper that it was bewitched to look like the night sky, a fact that she'd found in Hogwarts: A History. Harry's reverie was interrupted by the sound of a stool hitting the ground. A pointed wizard's hat perched atop it. It was so dirty and ragged that Harry doubted even his Aunt Petunia would allow it in her house. Maybe they just had to pull a rabbit out of it, Harry thought wildly before following the example of everyone else and turning his attention to said hat. After a few seconds of complete silence, the hat burst into song.

Oh, you may not think I'm pretty,
But don't judge on what you see,
I'll eat myself if you can find
A smarter hat then me.
You can keep your bowlers black,
Your top hats sleek and tall,
For I'm the Hogwarts Sorting Hat
And I can cap them all.
There's nothing hidden in your head
The Sorting Hat can't see,
So try me on and I will tell you
Where you ought to be.
You might belong in Gryffindor,
Where dwell the brave at heart,
Their daring, nerve and chivalry,
Set Gryffindors apart;
You might belong in Hufflepuff
Where they are just and loyal,
Those patient Hufflepuffs are true,
And unafraid of toil;
Or yet in wise old Ravenclaw,
If you've a ready mind,
Where those of wit and learning,
Will always find their kind;
Or perhaps in Slytherin,
Where you'll meet your real friends,
Those cunning folk use any means,
To achieve their ends.
So put me on! Don't be afraid!
And don't get in a flap!
You're in safe hands (though I have none)
For a Thinking Cap.' * Pg 125-126

Everyone burst into thunderous applause. Ron was muttering beside him about how mad he was at Fred. Harry forced himself to smile. Yes, trying the hat on was a lot easier but was it really necessary to have the whole school see it? As the students settled, Harry tried to guess what house he might fit into.

Professor McGonagall now stepped forward with a long roll of parchment. "When I call your name, please step forward and put on the hat. Abbot, Hannah, if you will."

A blonde girl with pigtails stepped out and after a moment's pause the hat shouted –

"HUFFLEPUFF!"

The sorting continued with Susan Bones going to Hufflepuff also, Terry Boot to Ravenclaw and so on until finally it was Harry's turn.

"Potter, Harry!"

As Harry stepped forward, whispers broke out all around the hall. "Did she just say Potter?" "The Harry Potter?"

The last thing Harry saw as the hat dropped over him was the necks of students craning to get a look at the famous Boy Who Lived. He waited as the hat sorted through his mind.

"Hmm, very difficult." said a small voice in his ear. "Difficult, Very Difficult. Plenty of courage, I see. Not a bad mind either. There's talent, oh my goodness, yes – and a nice thirst to prove yourself, now that's interesting…. So where shall I put you, Young Potter?"

Harry frowned at the brow of the hat. "You mean I have a choice?

"Why, yes of course!" replied the Sorting Hat in shock.

"Well where do you think I would best fit?"

The hat paused. "May I look around a little more?"

Harry nodded his permission.

SSHP SSHP SSHP SSHP

At the Head Table, Severus watched curiously as Potter was sorted. He'd been prepared to hate the boy on sight, but when he looked at him, he saw himself. Surely not… Dumbledore's golden boy couldn't have been abused. He snorted.

To his shock, the boy suddenly stood and paced this way and that. He then began to spin in circles. He frowned. "This is taking an unusual amount of time isn't it?"

Minerva nodded her agreement, as did several other Professors.

Dumbledore turned to them with a twinkle in his eye. "Alastair knows what he's doing."

SS HP SS HP

The Hat had been rifling through his memories for quite a while now. It gasped. "You were abused?"

"I guess so, Sir. I was their punching bag."

"Please, call me Alastair. I haven't been called Sir in thousands of years."

"Alright, Alastair. Have you decided?"

It grunted. "You have the courage of a Gryffindor, the heart of a Hufflepuff, and the mind of a Ravenclaw, but to do what you've done for so long – to stay alive under those conditions – points to the actions of a Slytherin. In Slytherin you can use all those traits to your advantage and change the course of the coming war – Voldemort is not dead, merely waiting."

Harry seemed to agree, so the hat shouted "SLYTHERIN!"

The hall went silent. The son of the lightest wizard and witch known to man, a Slytherin?

SS HP SS HP

Severus' eyes widened in shock. Lily's son was in his house. This was his opportunity to redeem himself.

"I'll protect him, Lily, I swear." He whispered, swearing then to take the boy under his wing, spying be damned.

SS HP SS HP

As Harry lifted the hat, he noticed that every student and professor had now gone silent in shock. Each stared at him with a look of disbelief, unable to believe that the Harry Potter was in Slytherin of all houses. Not even the Slytherins could believe it.

Harry turned to the head table, looking for guidance. Even the headmaster in the throne like chair looked surprised. Steeling himself, Harry took a deep breath and walked over to the table with the students dressed in green robes with silver trim. Every eye followed him. Harry subtly observed his watch, timing how long it took before someone reacted. It was five minutes before anyone came to their senses.

The headmaster cleared his throat. "Professor McGonagall, please, by all means continue with the sorting.

"Of course, Professor Dumbledore." she replied. So that was his name.

The sorting continued, with Ron going to Gryffindor. Another boy with dark skin, Blaise Zabini, sat down at his left and they waited for Dumbledore to speak again.

After the shock had settled, he stood up. "I have just a few words to say before we begin and they are Nitwit! Blubber! Oddment! Tweak! Enjoy the banquet."

As the professor sat down again, food appeared before them, weighing the tables down with the sheer amount. Harry dug in, never having seen so much food in his life. There was no one to stop him or steal his food. He selected a little of everything he thought he might like. A pale hand tapped him on the shoulder.

"Potter, how in Merlin's name did you get into Slytherin?" This was said by Draco Malfoy, whose silvery blond hair shimmered in the candlelight.

"The sorting hat put me here." Harry said, not knowing how much to reveal.

"We all saw that… but how? Everyone, and I mean everyone, thought you'd be a bloody Gryffindor, being from the lightest family in Europe."

"What do you mean? From what the hat said, being a Slytherin doesn't mean you're a dark wizard or witch."

This gave them pause. "Potter, don't tell me you don't understand what being a Slytherin means."

"It means you're ambitious and cunning."

"Oh, for Merlin's sake Potter!" drawled Zabini.

"Sorry. What is it you were going to say?" Harry asked.

"Urgh. Never Mind." he huffed.

Harry frowned. "Look, with the exception of my visit to Diagon Alley with Hagrid, today is my first day back in the wizarding world. I was left with the worst possible muggles – who used me as their slave and punch bag. I'm not sure about muggles in general, but I can't stand the ones I live with."

A girl opposite him frowned, a look of shock plastered on her face. She tried to wipe it off discreetly. "So, you grew up not knowing about our world? How are you even sitting here? I mean, we'll definitely help you make the right choices, but I'm just wondering."

"Yes, I did grow up ignorant. I took advantage of the Diagon Alley visit and got as much information as I could about the structures and so on. What are all your names?"

The girl introduced herself as Daphne Greengrass and continued to point out their peers. Draco Malfoy, Blaise Zabini, Tracey Davis, Millicent Bulstrode, Pansy Parkinson, Vincent Crabbe, Gregory Goyle and Theodore Nott.

Harry sat deep in thought as he nibbled on a piece of chicken. Zabini, Greengrass and Davis seemed helpful and much kinder than their peers. Millicent Bulstrode, Crabbe and Goyle appeared a little dull. Parkinson was a bitter looking girl who would take some time getting used to, and Malfoy and Nott seemed a little hard to crack. Finally, he spoke.

"I will take advice, but at the end of the day, the choice I make is my own." To his surprise, this made them smile and glance at each other happily.

Daphne nodded. "You just showed us why the hat put you here. You think ambitiously, yet you're cautious about what you say and rather sly. You definitely belong."

Harry's heart swelled. It had been years since he'd felt accepted.

"I agree with Greengrass, Potter." This came from Blaise beside him. From his other side, Draco said "I could grow to like you eventually." Harry nodded, that was a start. But he still had one burning question.

"If I may be so bold to ask, what is with the surnames?"

Draco decided to take this one, being the most knowledgeable. "That's easy Potter. It's a pureblood thing. We grew up with alliances between families. Because these are more formal, parties are required to be addressed as such. It's an automatic carry over here at Hogwarts."

Harry could understand that. "That makes sense. A pureblood is someone with seven generations of magic right?" He'd read it in a book he'd purchased.

Tracey Davis, who'd been quiet until then, smiled and said "Yes. You're a half-blood – your mother was muggleborn and your father, pureblood."

Nott spoke up as well. "Muggleborns are also sometimes known as mudbloods. It's an insult, meaning dirty blood. I just wanted you to know so that you won't be too upset when you hear it around the common room. It's habit for a lot of purebloods."

Harry frowned. "As long as you don't refer to my mother in that way, I'll keep my emotions to myself." He said this with a slight air of formality. Daphne smiled at him, catching his second meaning.

As the feast continued, Harry observed their way of doing things and enjoyed listening to the conversations around him. He found it was one of the best ways of learning. At one point, his new head of house, a man with dark eyes, quirked his lips in acknowledgement.

SS HP SS HP SS HP

At the head table, another conversation took place.

Severus had just begun to dig heartily into his mashed potato and gravy, when Minerva McGonagall spoke. "Severus, I can't believe young Harry is in your house."

He took a deep breath. He'd known the second young Potter had been sorted into that this conversation would happen. "Yes. He is."

She sniffled. He turned and saw that Minerva's eyes were brimming with tears. "Minerva? What is it? What's bothering you?" Minerva was the one person he could be real around. She'd seen straight through his mask of coldness the day she met him. Over the years, her guidance had made him who he was today. He'd even once heard her say that she loved him like he were her own child.

"The day Albus brought him to his aunt and uncle, I sat outside their house and watched them. Severus, they're the worst sort of muggles ever! The son, he hit his mother because she wouldn't give him a sweet. Albus claims that Harry was safe and being guarded, but if that's what happened ten years ago, I dread to think what's happened since then."

Severus' eyes turned hard. "You've noticed too then?"

"He's so thin! Oh Severus, what are we going to do?"

He pondered this. "First, we observe. If Harry opens up, then we address it. If he hasn't by the end of the week, we book him in with Poppy."

She gaped at him. "Yes, good idea." She was silent for a few moments more, before she burst out "You called him Harry!"

He watched the boy in question for a moment before sighing. "It's what Lily would've wanted."

And as black eyes met green, he knew he'd made the correct decision.

HP SS HP SS

Dumbledore ended his speech by saying that anyone who did not wish to die a painful death should avoid the third-floor corridor. After the school song ended, everyone rushed off to their respective common rooms.

HP SS HP SS

The Slytherin first years followed their Prefect, Marcus Flint, through the chattering crowds and down into the dungeons.

"This is the entrance to the Slytherin common room," Flint said, stopping in front of a bare stone wall at a dead end. "This week's password is 'Slytherins Rule'." As he said this, the stone wall rearranged to reveal a beautifully decorated room. Harry looked around, admiring the green lamps hanging from the stone ceilings, the wing-backed chairs by the fire, and an elaborate mantelpiece. He saw some older Slytherins sitting around tables, chattering about their various holidays and what they were looking forward to.

The prefect directed the girls down one corridor and the boys down another. "Boys, don't even attempt to go past the first torch to the girls' dormitory or everyone will know it. Now, you've got five minutes to tidy yourselves up before Professor Snape comes for his annual start of term speech. Go!"

The first years all looked at each other before racing off to sort themselves out. Harry's mouth dropped open as he entered. Six four poster beds were positioned around the room, each with lush green velvet curtains. Each bed was surrounded by a mahogany wood desk, wardrobe and shelves. Harry quickly put his robes and uniform out for the next day and put what he could away.

HP SS HP SS

The new students stared in awe as Professor Snape entered the Common Room with a flourish. He smiled internally. This was his favourite part.

"Good evening, students. Welcome back to Hogwarts for another year. If you do not know who I am, my name is Professor Snape and I teach Potions. Being in Slytherin means other houses may treat you with contempt. Protect each other, stay together and for goodness sake, don't make yourselves look like a fool. Any questions?"

There were none, so he ordered them to bed, staring at Harry as he went. From afar, his eyes stood out. Up close, they were like pure emeralds. Just like Lily.

He highly doubted he would sleep tonight.

A/N: Another story has begun. This is the LONGEST chapter I've ever written. I hope you enjoyed it, and yes, I know it's rather cliché. In regard to Severus' behaviour, he loves Lily with all his heart and bitterly regrets all the things he did to hurt her. When he sees himself in Harry (with the signs of abuse), he believes that this is his last chance to make it up to her. In regard to pairings, this will not be slash. It will definitely be Harry/Daphne once they're older, but I haven't figured it out.