Notes: I do not own the rights to Harry Potter. All characters and subject matter are the property of their creator, JK Rowling, to whom I am most grateful for creating my favorite sandbox to play in.

Chapter 1: Ten Years of Preparation

The past ten years had been anything but easy for Severus Snape. Of course, if he wanted to properly assess the situation he would relent that the majority of his thirty-one years on the planet had been anything but easy. It wasn't quite the same on this end looking back to what it had been like to live through his trials of years past, starting his life as an unloved little boy looking ahead to a future that seemed nothing but inevitably treacherous-if he wasn't killed before he even reached adulthood. Even when Lily entered his life, that one ray of hope and happiness in a world of misery and darkness, he didn't really see much of a future for himself. It was difficult to plan for beyond the same week when all manner of horrid events could unfold in the meantime. Inevitable meltdowns he'd needed to be prepared for, incidents that usually ended with Severus nursing a bloody nose and scrapes and bruises. On the worst nights, it involved finding another place to sleep when his parents kicked him out at the height of their fury, one of their rare displays of unity. The fights between his parents had over time only become worse and more one-sided, Tobias' violence and anger seeming to be the only things that flourished in the last house on Spinner's End after a time. Watching his mother diminish further and further into a husk of a person was perhaps the most painful experience in his life.

And eventually, when he was of age, he realized he'd had to throw in the proverbial towel and leave to make a life for himself away from them and their problems. There was nothing he could do to help them, nothing he hadn't tried in the past to no avail. Out on his own, stumbling through life like a fawn on shaky legs, he was never at a loss for challenges or difficult decisions. He usually made the wrong ones, chiefly among them the choice to work for a man who then called himself Tom Riddle. So many terrible things followed in the wake of that decision, and although he had not fully known the severity of his choice, the extent to which Riddle was willing to go to see his ideal world born, he knew he was making a poor choice. Even clouded by pride and a desperate need to prove himself Severus knew there were better choices. Ones that were far less morally grey, anyway; he'd had more than one potions master offer him a job as their apprentice before he'd even left school and though the offered pay was modest it would have been enough to sustain him. He could have worked through the day in their laboratories and gone home at night to continue working on his own research of spellcraft and brewing and easily had his findings printed in respected journals regularly.

It all just seemed too humble at the time. Now the reminder if his grossly inflated ego only disgusted him. He tried not to think about who it reminded him of.

There had eventually been an apprenticeship and he had proven his Potions Mastery, but that wouldn't come until many months had passed him by and not because he was a bright-eyed and hopeful young man looking to start a new career path. That story belonged to someone else. For him, his late entrance into the world of legitimate potioneers was purely tactical, entwined tightly in an elaborate plot only someone like Albus Dumbledore (or Tom Riddle) could have produced. He received his title only to polish a woefully short resumé in preparation for a far worse job than the inanity of endlessly scrubbing cauldrons and brewing whatever draughts suited his master's whim. He was to work as Slughorn's assistant for a time before taking over his position entirely, the youngest Potions professor the school had ever seen. Although he had been Dumbledore's man longer than their staged encounter (there had to be some false memory to show the Dark Lord should he ever get the inclination to look) indicated, secretly feeding him and subsequently the Order just enough information so as not to arouse suspicion from either master, it turned out that his work was simply not enough. Not enough for Dumbledore, who apparently wanted to keep a closer eye on his spy, and, not enough for the Dark Lord either, who delighted at having his most trusted servant so close to his greatest adversary.

Not for the last time Severus wished he'd not gotten himself into such a predicament. He had never been comfortable around children, and though teaching came easily when he tutored people in the past, they had at least wanted to understand what he was trying to teach them. Interest, if not in the craft but at least passing the course, had been enough to make those interactions tolerable, but many of the students who came through the school were far more interested in grandiose incantations than the subtle art of potion-making. There was absolutely no hiding their disinterest and for Severus there was absolutely no hiding his disappointment and occasional disdain. He knew it wasn't right, but it was hard not to bite out a scathing remark at the one student who seemed utterly incapable of following the simplest instructions. If the craft he taught had been anything else-cooking or pottery, perhaps-it would not vex him so, but when errors could endanger everyone around them (from flesh-melting goo to toxic fumes that could incapacitate them for several hours) he rarely let them slide without harsh rebuke. He was not the happiest back in a place with so many bad memories in the company of people he just didn't understand, but he cared very much for the students.

The only ones who really saw this were his Slytherins, though. He'd taken them under his wing far more readily and with far more ease than he'd taken to the teaching position itself. There was an easy kinship there; he had been in their shoes not very long ago at all and he knew the pain of being ithat/i group. Even the youngest of Slytherins felt the sting of iotherness/i the school put on them, some ostracized from the moment they were Sorted (it was not uncommon for boos to be heard throughout the Great Hall when a young student was Sorted into his House, with no reproach from any staff members save himself), and doing all that he could to give those students a place where they could feel welcome and like they belonged came as easily as breathing to Severus. They deserved it, needed it, far more than anyone else wanted to realize. Under his guardianship, Slytherin House became more of a family than a simple group of like-minded students, and the Common Room quickly became their home, a safe haven from the judgment of the outside world. That wasn't to say there weren't bumps along the way; though he always endeavored to defend his students (and one of the rules he'd created in the beginning was to always show a unified front outside of the walls of their Common Room) he realized they were not perfect. However, disciplinary action was always brought forth later, usually during a meeting in his office, after the student had enough time to decompress after the event. He rarely gave his own students detentions only because his fellow staff members seemed more than eager to dispense punishments their way, often harsher than necessary after further examinations were made.

But then that had been the way of things for years at Hogwarts, hadn't it? Not much changed between his departure from the school in 1978 and his return to it in 1980. The reputations their parents, many of whom had been Death Eaters, preceded them and their House only further diminished them in the eyes of others. Despite all that worked against them, though, Severus' students had managed to succeed beyond his hopes. Although his first few years as a teacher had been incredibly difficult with a lot of growing pains and shared frustration between he and the mentor Albus assigned him (none other than the Head of Gryffindor House, Minerva McGonagall) he finally fell into a rhythm. Both his mother, who had taught him a bit of brewing in the past with a critical and unforgiving tutelage, and Minerva drew out a similarly strict disciplinarian in him. Within months of his first solo taught class, which occurred sooner than planned (Horace had decided to retire at the end of the first semester rather than the end of the school year as planned), Severus was able to hold a class' attention without ever raising his voice above a near whisper. Although specific rebukes were often necessary (and often paired with deduction of House Points or assigned detentions) when dangerous mistakes were made, it didn't usually take more than a look to settle any lingering unruliness. It was hard to pinpoint precisely when his observations of the two women's mannerisms finally clicked and became his own, but he was glad when it finally did. He was nearing his wit's end trying to manage a classroom full of children, Minerva loved to remind him, not much younger than him.

'You know, I've told Albus myself several times you simply do not have the temperament nor the ability to teach.'

Maybe her prodding had finally done it. She wasn't wrong about the first point, but the second left him seething. He was more than able to teach-he knew potions probably as well she she knew transfiguration. The way she displayed the gleaming House Cup and Quidditch Cup in her office (which he had to see during their weekly 'training' meetings) only served to fuel his thirst to prove himself. Whether that had been the plan all along or a convenient coincidence was of no consequence; it worked, and he managed to lead his students to the House Cup for the last seven years running. They'd even managed to snag the Quidditch Cup six out of those last seven years, only losing it by a hair's edge once to the Gryffindors. Minerva had been near intolerable the whole year following (despite the House Cup sitting gleaming in Severus' office) and he refused to allow her the satisfaction of taking it again. For someone who had always hated the sport and used every excuse in the book to avoid matches as a student, he became quite invested in the details of the school's Quidditch Competitions. If he could show his students the support they needed while simultaneously working to give Minerva less fodder for her smug attitude it was time well spent. When the first set of Seventh Years that had been taught exclusively by him received their NEWT results his work was finally able to speak for him. Although he'd been warned against being as selective as he was when allowing students into his NEWT-level courses, he still managed to boast far more students with Outstanding marks on their NEWTs than Slughorn had at his best despite the smaller class sizes. He had smirked across the staff table at Minerva, who did her best not to look at him, but that was only the surface of his pride.

Beyond marks and behavior and Quidditch competitions he'd managed a far greater achievement; Slytherin House, under his leadership, was churning out the smallest number of blood purists than it ever had. Especially in recent years, with the influence of Grindelwald and then Voldemort to contend with, more Slytherin students left to join radical organizations than did not. It was incredibly easy to fall into the trap laid out; acceptance and a chance to prove themselves were far too tempting an offering to people who had been cast aside for the better part of their formative years. If their parents had been supremacists themselves they were nearly helpless to do anything but fall right into their open hands. Though Voldemort was not in power any longer and had not been for some time, there was still just as real a chance of students leaving with twisted notions of superiority in their minds as there had been when he was still actively recruiting. Severus understood that his task would be much more difficult if Voldemort was around to recruit, but he was certain that he would still not lose more than half of his students to the madman as Horace had. Where Slughorn had been more interested in the students who showed potential to help him personally (either with the influence of wealth and status or ability in his class), Severus devoted himself fully to mentoring his charges. In a weird sense, they had almost become like his children, and since most of them had been raised by House Elves and nannies more than their parents, he supposed he rather was like a father to them now. It was a side that was never shown to any other students, but those students had more than enough support, and it wasn't as though he could provide the same level of care to four hundred students as he could one hundred. Even that was a challenging task.

And yet, although his accomplishments in this position had been great (even the most dubious members of staff had finally relented to that), that was not why he was back at Hogwarts. It was not why he had stayed far longer than Voldemort's original defeat. Without much explanation (for the man seemed to delight in vague instructions and half-truths) Dumbledore had made it clear that the war was far from over. Voldemort's supporters obviously still remained after his defeat, but those who had been most vocally supportive had gone to and remained in Azkaban. Although it seemed as though the worst was over (even if they broke out what was the worst a ragtag group of maniacs could do?) Dumbledore seemed convinced Voldemort had not been defeated for good. Perhaps somewhere Severus felt it too, most notably in the Dark Mark that had not disappeared from his forearm the night Voldemort 'died'. If he had actually done so it should have disappeared completely, but it had only faded, a faint wisp of what it had been, but still very much there. He guessed that was the state Voldemort entered and had been in since that Halloween ten years ago. And that meant, when he did return, he would have unfinished business with a certain child who was now old enough to attend the school he'd remained a teacher at all these years. If he had been willing to raise his wand to an infant and utter words that summoned death (after murdering his two parents not minutes before) Severus had no doubt in his mind he'd come looking to finish the job the second he could do so.

Severus was meant to prevent this from happening at any costs. Although the plan had been laid out differently than the memory he and Albus created showed-for there needed to be far more adversity between them to ease the Dark Lord's mind when he decided to look upon Severus' memories, an agreement made between a Headmaster and his young employee before they'd even known who the prophecy was about, the goal was the same; do all that is necessary to prepare whichever child the prophecy speaks of to face off with Voldemort. Severus had still ultimately been hesitant to take the news of the prophecy to the Dark Lord despite Albus' insistence that it was the best choice to make; they had no way of knowing who Voldemort would ultimately target, though they had some suspicions, and although Severus generally disliked all people, he did not enjoy the thought of being responsible for someone's death. Neither he nor Albus had suspected he'd go after an infant, though, and when the measures made to protect the family Voldemort chose to pursue failed, they quickly scrambled to make adjustments to the plan. That was where Severus' duty to Albus continued, and for years he waited at Hogwarts for the day The Boy Who Lived would arrive.

He sneered at the thought of it, directing his gaze to the high table as the older students filed into the Great Hall. No doubt the boy would be joining them with an even bigger head than his father had years ago. The only thing that made it worse was the fact that Severus had sworn an oath to protect him, a task that would no doubt be made exceedingly difficult by the spawn of one of the most egotistically reckless people the school had ever had the misfortune of hosting. When one's father trounced around at every full moon as a stag in the company of a werewolf there was little wiggle room to do any better. Although he had many struggles as a new and incredibly young teacher ten years ago, he had a feeling the most difficult years were about to begin.