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AN1-2020/12/20: Chapter now betaed by Miette and dtone12, thank you :)

As he uttered the last words of the vow, Severus felt like a shape of lead setting on his mind, his fires losing intensity suddenly. He renewed his focus on the flames and felt the shape shrink and lighten until it felt as if a light silken sheet had melted into his potions fumes and covered a little part of his mind. Severus knew he could not let Dumbledore suspect anything so hoping he had at least lessened the vow, he let his attention return to the Headmaster's office.

The Headmaster was observing him. After several minutes, seemingly satisfied, he spoke.

"There is another matter I need to bring to your attention. Mister Potter saved your life, Mister Snape. He is neither a friend nor a member of your family. Your families have no ties. You two are in fact what I would call Arch-enemies. It means Magic now recognizes that you, Mister Snape, owe a life debt to Mister Potter. Mister Potter can choose to collect this debt anytime he wants to, but Magic will only consider the debt paid when what is given is worth as much to you as your life is."

He paused, watching his students.

Potter's face was a mix between surprise, resignation and satisfaction.

Black was gleeful.

Severus was white.

Without Occlumency, he would have fainted. Or gone into a rage. But no.

"Is that all Headmaster?"

Seemingly unconcerned, as if he had not dropped a bomb to end Severus' wonderful evening, Dumbledore answered.

"As long as you have no question on life debts, you may go Mister Snape."

Shaking his head to indicate he had none, Severus left the Headmaster's office while the two Marauders remained. He went down the stairs in autopilot, thoughts circling through his mind. What had really happened there?

Severus slowly paced in his lab as he pondered the memory. Even today, he still had trouble accepting how callous the Headmaster was. How easily he had dismissed one of his students, only because he was a Slytherin. How could he have become Hogwarts' Headmaster when he despised one of his House so? Surely, one of the Oaths he had sworn when becoming the Headmaster should have prevented this kind of behaviour?

Oaths were tricky, as he had learnt this year. He could not wait to be apprenticed and study this kind of Magic.

Severus smiled bitterly as he watched his memory self rack his brain to find a solution out of this mess.

Severus knew he had tweaked the unbreakable vow but would it be enough? He had to research the functioning of bonds but was pretty sure there were no interesting books in the library on the subject. He had almost finished the seventh-year Defence Against the Dark Arts curriculum and magical bonds were only given a brief look. Bonds were considered advanced and dangerous magic because most of them were dark. Indeed, most bonds required a sacrifice. Severus was surprised that unbreakable vows were not forbidden by the Ministry because the subject lost part of his freewill. He supposed it was too useful to ban.

Severus wondered if he could bring his questions to Lord Malfoy. It would be difficult without knowing the boundaries of the vow but if he approached it like a research project of his own, it might work. Severus would have to be careful in wording his request not to raise his sponsor suspicion. Bonds were not common research for fifteen years old after all. But this should help Severus for his understanding of both the unbreakable vow and the life debt.

Severus felt his stomach tighten when the thought he might owe a life debt to Potter of all people escaped his mind's laboratory fumes. Suddenly, his hands were shaking badly. In fact, his whole body was trembling. Adrenalin must have run out and now that the tension was leaving him, Severus' control was slipping. As quickly as he could, he went to his physical potion laboratory where he sat on the cold floor, rocking himself and focusing on his mind's potions fumes until he felt like he could walk.

Severus sighed, he knew the rest of this year's memories would not get better. But something Dumbledore had said in the memory nagged at his mind. To pass his OWLS on his own... Why not try to pass his NEWTS on his own? He had studied in advance in Potions, Defence Against the Dark Arts and Transfiguration already. He might manage a passing grade in Arithmancy and Runes, depending on the date of the exams. It would have to be before September if he wanted to find an Apprenticeship. Worse, he needed the results before September so... NEWTS at the end of July if there was a session. He should also try for Care of Magical Creatures but he would lack two years of practicals.

Merlin, the only NEWTS he knew he would pass was Potions.

He had to look into it. It could be the answer.

But first, he needed to finish this trip in his memories.

Severus grimaced. His temper had always been short, and even atrocious in his third year when he had had to contend with Marauders, brewing for Mother, fear for her as she remained behind with his father, guilt for leaving her with him, stress from studying Transfiguration, frustration with Lily, growing pains… He had thought he had reached the worst he could be back then. Werewolves had brought out a whole new level of meanness in him.

Severus watched his memory shimmer in front of him, reluctant to enter it but knowing he had to. Scolding himself for being afraid of taking responsibility for his past actions, he went in.

One week after the werewolf... prank, Severus nerves were frayed. Ready to snap at anything. The younger Slytherins—and even the older ones—avoided him. Only Jonathan and Evan dared sit next to him, chatting quietly and sending worried looks his way.

He was pale as a ghost. His eyes were shuttered, black like the voids in the universe. Dark shadows under his eyes made him look like he had been punched in the face twice with utmost precision. His hair hung in front of his face, greasier than ever. His mouth was frozen between a perpetual scowl and a wild snarl.

He was frightening. He did not care.

He had hurt several of his peers during the last Defence Against the Dark Arts class. They were supposed to practice the Accio spell for the third session in a row. His spell was seldom strong enough to take the book from Jonathan's hand and fly it to his own. Ironic, knowing his first bout of accidental magic had been to bring his ball to him.

This time, Severus had taken the book from Evan's hand. He had also wrenched the books from everyone practising and inadvertently brought all of them on Corbin's head—Corbin was a haughty Ravenclaw Muggleborn—, a few rebounding on other classmates. He had been quite happy with this unexpected feat because at the time, he had been angry at the Raven for mocking Severus' lack of success while lazily accioing his book from his partner's hands.

Their idiot professor only told Severus to mind the power of his spells then returned to his desk while the entire class gaped.

Most laughed when his next try only produced a small cloud of smoke.

When the bell rang, Severus stormed from the class to return to his common room, Jonathan and Evan trailing behind. He immediately began his homework, focusing on the happiness charm theory and how to best structure his essay to answer the question "How can you enhance, or on the contrary lessen, the effects of the happiness charm? Explain and illustrate with examples which will be practised during class."

Jonathan and Evan settled next to him and began talking about their Potions essay.

Severus wanted to close his eyes in shame, not to watch what was going to happen next.

His memory self was scowling, silently muttering to himself. He was in the middle of explaining how a giggling potion could enhance the happiness felt by someone under the happiness charm, but only if the person was not ashamed of expressing his joy with giggles—meaning it would have absolutely no effect for Severus and might even nullify the impact of the charms—when he heard Jonathan.

"Okay Evan, I don't see where you read that ladybird's legs can be used instead of frog's legs in the confusing potion. It does not make sense when..."

Slash. Claws ripped in front of Severus, almost startling him. He growled, pushing the wolf behind his mind potions fumes.

"See here," explained Evan to Jonathan, "for a memory potion, they use ladybird's eyes, so I thought in our case we could extrapolate and…"

Large yellow canine eyes were watching Severus as he tried to continue his essay. He felt his hairs rise. He had to focus on the essay.

"Come on Evan, why do you think…"

The Wolf was growling now, preparing to pounce on Severus.

"Jonathan, you are so narrow-minded. Be a little imaginative. I am sure we can translate some ingredients from this memory potion for our project and..."

"Can't you stop blabbering you idiot," snapped Severus while he struggled to ignore the wolf jumping above him. "Ladybirds are known for retaining memories while you want to confuse someone, meaning you want him to lose his memories or at least his certainty in his memory. How is it so hard for even your little brain to comprehend?" he finished, his words razor edges that cut easily into his friend.

"Severus," intervened Jonathan. "It is not that evident. You can discuss…"

"No, you cannot. You are only trying because you are being a negotiator," Severus sneered derisively. "Always avoiding conflicts because you cannot stand them. Better an idiot than a coward," he finished, standing suddenly to escape to his potions lab, leaving his two stricken friends.

Breathing heavily, Severus let himself fall on the ground, shaking.

The look on Evan's face... and Jonathan's...

Why did he say those words to his friends? To shut them up so he could concentrate on not thinking about the werewolf he answered himself. But he could have asked them to stop speaking without being so hurtful... The fear was controlling him. Day and night. He spent his nights in the passage leading to the room, surrounded by growls and yellow eyes. During the days, he replayed the memory in his head. Occlumency did not even bring him peace. He had tried to lock the memory in his mind's lab, but potion ingredients kept morphing into werewolves' parts that threatened him from their shelves and tried to get out of their jars. Werewolves' growls came from his bubbling cauldrons, over and over. Only focusing totally on a complex subject brought him solace.

It was no excuse. He had to apologise. If they let him.

He could not hurt them again. He had to find another way.

Severus skipped dinner, stomach hurting, while trying to compose his apology. When he finally went back to his room, Jonathan and Evan were on Jonathan's bed. They ceased talking when he opened the door. Severus closed it carefully. Hanging his head, he went to stand in front of them. Evan glared. Jonathan kept his face blank.

"I'm sorry."

They stared. Severus swallowed thickly.

"I am really sorry. Will you... still be... my friends?"

Severus hated himself for the pleading in his voice. Weakness. They were his friends, it should not matter. They were Slytherins. Of course it would. Wouldn't it?

Evan and Jonathan looked at each other then sighed. Jonathan stood up and dragged Severus on the bed between the two of them.

"Of course we will, you idiot," said Jonathan.

"Yeah, you can be quite dumb for a genius," added Evan smirking.

Severus felt the tension inside him uncoil but fought to remain vigilant.

"What is going on Severus?" asked Jonathan. "You look like a cadaver."

"Even more than usual," piped in Evan

"You were quite relaxed—for you—this year but suddenly one week ago you just... changed!" continued his friend, ignoring Evan's intervention.

"Now you are scaring the firsties and the seventh years alike!" added Evan helpfully.

"I bet it got something to do with the Marauders falling out," said Jonathan, watching Severus carefully.

His friends were looking at him earnestly. He should tell them. They could help him. Maybe.

The moment he decided he was telling them that Lupin had almost killed him; he felt the sheet covering his memory stir. Clearly, the oath was at least partly active.

Severus frowned. He prodded the sheet in his mind, watching as some parts felt welded to his memories while others just rested on them.

He might be able to tell the incident if he censored some information. Magic recognised intent. Dumbledore's main concern clearly was Lupin's safety and anonymity—as well as his own career, because allowing a Werewolf to study in Hogwarts could destroy the Headmaster's reputation. The oath should have focused on this intent. It should allow Severus to say he had almost been mauled by a Werewolf because of a prank. His slytherin friends should draw the right conclusion quickly enough. Lots of shoulds in this but he had to try. For his sanity.

"A... prank happened," said Severus carefully choosing his words while closely looking at the sheet in his memory. It did not move.

"A week ago, I had a close and unfortunate encounter with a... creature."

While Severus was speaking, the sheet had begun weighting more and more on his mind. Severus had to shift the word Werewolf to creature to avoid suffocation. Even then, he felt like he would never be able to think again. The sheet was putting heavy pressure on his mind. He tried to add that the Marauders had done the prank but found he could not speak, no matter how much he willed himself to.

"Severus! What's wrong?"

His two friends looked alarmed. He realised he was breathing hard, with difficulty. Alright, time to stop speaking about the incident.

All at once, the sheet released its hold on his mind and he could breath. And think.

"Okaaaay," said Evan. "You clearly cannot speak of this... prank easily so someone important made you take a Silencing Oath."

"Unbreakable oath I think," added Jonathan, thinking furiously. "It's the only oath people in this school do not consider Dark with the exceptions of Slytherins. Although it should have prevented you from speaking of it, even in the vague way you did… Unless it was badly cast…" he finished doubtfully.

"Unless Severus is a genius as usual," said Evan emphatically. "Hmmm, it could have been a Slytherin if he wanted to protect his secret... If he owned a creature dangerous enough to scare Severus… Blackmail material if you ask me."

"No, Severus said it was a prank. No Slytherin would consider a creature that shook Severus that badly prank material. No Hufflepuff either I think. It means Ravenclaws or Gryffindors… I just don't see any student casting an unspeakable oath or you agreeing to take it for a student in the first place. But I don't see any adult playing a prank on you either," said Jonathan frustrated.

He shook his head.

"Anyway, it was sure Severus would see the creature at some point but be expected to survive… When you say prank, I think Marauders, especially as they were not their usual united group this past week, but I don't see them with a dangerous creature…"

His eyes widened and he looked at Severus in alarm. "Wait, you told us you suspected Lupin of being a Werewolf. We agreed the signs were there. You discovered proof he really is..." trailed off Jonathan, watching Severus for some sign of agreement.

Severus did not dare say anything, feeling the sheet alert in his head. He only gave Jonathan a little smile.

"But no way Severus would have taken an oath for them," said Evan, frowning. "So… Dumbledore?" he asked, both disbelieving and resigned

Again, Severus smiled. He was exhausted. His head was pounding. He had managed to talk to his friends.

"Of course," snarled Evan, fist pounding on the bed. Again and again.

Evan remained silent, murder in his eyes, before letting out a frustrated shout.

"Must have been a really close call to have you so out of sorts. And with the oath preventing you from speaking of it... Merlin, Severus, no wonder you are snappish!"

Severus only shrugged. What could he say?

"Were you hurt?" asked Jonathan, suddenly worried.

Severus shook his head mutedly and his two friends visibly let out a breath. They began arguing about ways to denounce the incident and Dumbledore's involvement.

Suddenly, Evan turned to Severus and said:

"Have you tried looking for loopholes in the oath? I don't think you can tell us the exact wording but seeing you managed to tell us something, there must be a weakness."

Jonathan frowned.

"It sounds unlikely from Dumbledore but Severus did talk to us."

In truth, Severus had been too focused on not thinking about anything Werewolf to look for any loophole. In fact, he wanted to slap himself for assuming any oath crafted by Dumbledore would be perfect if not for his Occlumency. So, weaknesses.

I, Severus Tobias Snape, swear never to talk...

Hmmmmm he should be able to write about the incident. Or even show his memory...

of tonight's events to any person...

Ah, what qualified a person? Would a Goblin be a person or a creature... or both? And which creature would want to help Severus?

A Ghost maybe. The Bloody Baron gave advice to Slytherins sometimes.

Other than those present in this office tonight and Mister Lupin. Those events include the preparation of the prank for Severus Snape, the prank itself as well as the discussion in this office. So be it.

Severus really had a hard time calling the incident a prank. Could this difference of view give him some leave away? He had been able to use the word prank. But he had had difficulties telling Evan and Jonathan details about this prank so it clearly was not enough. Also, the word Werewolf was not in the oath but he had not been able to say it, the oath reacting violently. How strange… Bonds really were complex magic. He needed to find more information.

But first, to test his theories.

Under the curious eyes of his friends, Severus went to retrieve some writing material. He settled on his bed.

I was attacked by a werewolf. At school. It was a prank.

I fear Werewolves. I learned about them at school. I hate pranks.

Severus blinked. He had not written what he thought he had. He frowned, concentrating on his writing and augmenting his potions fumes.

I saw a Werewolf too close. I am afraid at school. People have funny definitions of pranks.

That was not working, although he had been able to write the word Werewolf. One theory done until he found someone who could lend him a pensieve to try to show his memories to his friends.

Alright, he needed to find the Bloody Baron.

The slytherin ghost was a taciturn sort although he always helped the first years find their way in the labyrinth the castle was. All Slytherins knew that if you wanted to talk to him, you had to stand in the corner of the common room where three stone snakes were entwined.

Why here was a mystery but it always worked. When the Baron appeared, you asked your question and he would either answer you or disappear. Severus had not talked to the Baron since first year. He had noticed the prefects, the queen and the king were the ones who called for him the most.

Severus waited less than two minutes before the Baron appeared.

"How may I help Slytherin's genius?"

Severus knew he had not completely hidden his surprise. There was pride in the Ghost's voice.

"I will try to tell you something important," blurted Severus, unbalanced by the recognition of his worth by his House's Ghost.

"I see," said the Baron.

Severus believed him. He felt like the ghost understood a lot from these few words.

"Say what you can, snakeling."

Severus smiled, watching himself bristle at the term. Of course, he was a mere child compared to the Baron. He really should speak more with the Ghost, if only because he was curious about the genius title.

Back in his memory, he was choking on his words. So much for that theory.

"Why did you think you would be able to talk to me, young Slytherin?"

Severus breathed heavily.

"I thought maybe you would not count as a person."

He waited uncertain, knowing he might have offended the Ghost but unwilling to lie.

Instead, the Baron gave him a sad smile.

"I am honoured you were not able to talk to me."

Severus frowned. What did he mean?

Before he could ask, the Baron was talking again.

"Hogwarts' first priority is her children. But how do you protect some when it means abandoning others?

She was created by human beings through Magic; as such she is as fallible as any of them. She chooses her Headmaster, one of her criteria being he must have an almost equal representation of the four Houses traits within himself. Sadly, it does not mean he will love all his students equally. Hogwarts can not foresee how outside events will affect her chosen. But there is also hope that people can change..."

He sighed soundlessly.

"These days, it almost feels like Hogwarts is fighting against herself. How can you win against yourself without losing?"

The Baron disappeared before Severus could even think about asking a question.

That was weird, he thought as he walked back slowly to his room. The Baron must have a reason for his speech but it left Severus baffled. Same as some of his discussion with his Mentor. What stuck with him though was that the Ghost had been honoured by Severus' inability to speak to him.

Severus nodded to himself as he watched the memory. Magic was intent. Severus had unconsciously considered the Ghost the equal of any other magic beings, thus honouring him but preventing Severus from speaking to him of the Werewolf incident. Passing his NEWTs early to begin studying Oaths and other very interesting Magic was definitely appealing. Though it would mean not seeing Evan and Jonathan everyday during the next two years.

In his memory, both his friends looked at him expectantly as he entered his room. He shook his head and set himself between the two of them.

They remained silent, enjoying the comfort their closeness gave them.

Jonathan was the one to speak.

"While you were gone, Evan and I thought of something."

He hesitated then continued.

"Lord Voldemort wants to improve creatures' conditions. I think he would support you if you managed to talk to Lord Malfoy about the prank but…"

Severus nodded. He knew Dumbledore had had a point. But he wanted to have the choice whether to tell or not.

"We don't care," said Evan vigorously. "If you want us to, we will work with you to make the Marauders pay for what they did. Even if it works against Lord Voldemort's stance on the creature issue."

Severus smiled gratefully. Politics were important to Slytherins. Going against it meant a lot from his friends.

"It's enough you know for now. I just need to find how to break the oath."

They remained in their room and played chess, allowing Severus to focus on the game and forget about Werewolves for a few hours.

That night, as he lay in bed, sleep refused to come to Severus. His brain was working furiously. He could not let his fear control him anymore. He was hurting his friends. He needed to get a grip. Werewolf teeth flashed in front of his eyes and he shivered. How could he feel safe again? He knew he would not be able to defend himself against a Werewolf thanks to his traitorous wand. How ironic. He had faced death and yet... Or did his wand consider he had failed to face death because of Potter?

No matter. How could he win against a Werewolf without his wand? Or maybe… Yes, he had to find a spell that would work no matter his lack of power. Furiously scanning the numerous spells he had learned, Severus came to the conclusion none were suitable. Either they demanded too much power or would not affect the wolf. Indeed, magical creatures were resistant to many spells that worked on Wizards, thanks to their innate magic. He had to create a spell that required little power and hurt a magical creature… so a spell that used the magic in the creature to hurt it… yes, the more you had magic in you, the more effective it would be….

But it would take some time to work the spell out. During this time… he would concentrate on his anger instead of his fear… and unleash it on people he did not care about…

Severus smirked at the thought from his memory self. He was proud of his spell. More of a curse really.

Sectumsempra.

His curse opened deep gashes in the body of the creature to drain the magic from it until it died. It could only be reversed by his counter-spell, Severus had made sure Finite Incantem or other such generic counters did not work. He had tested it on himself to be sure. He knew it was not one of his smarter moves but he had been... upset at the time.

A side effect of the gashes, which were necessary to reach the Magic of the creatures, was that the spell worked on all living creatures, magical or not. It comforted Severus that his spell would also work against his father if he ever dared come back.

The spell did not require much power because it fed on the magic inside the creatures. Non-magical ones simply bled out. The spell could not feed on their magic but they did not have magic to strengthen their body so the blood loss was enough to kill them.

Power from the caster was only needed to open the first gashes. Skin usually was fragile so only a small amount of power was needed.

It would require a lot more power to pierce a dragon's hide but in this case Severus would cast two Sectumsempra in a loop. The first one would be for the eyes or tongues, soft and unprotected parts of the dragon. It would begin draining magic from the dragon. Severus would then cast a second Sectumsempra linked to the drained magic and aimed at the dragon's body. The second spell would take power from the dragon's lost magic instead of Severus', allowing for more power without risking an exhaustion of his magical core. The more the spell worked, the more it drained magic, the more powerful it became.

This kind of casting was Dark and forbidden. Mother had made sure Severus mastered it. It was precise and complex, the more dangerous part being the creation of the link between the outside magic and your spell.

One had to be careful not to absorb the foreign magic because it could overflow his core or taint it. The results were either death or madness, right then or years later.

Severus had been careful to construct his spell so the drained magic was not absorbed by the caster but by either earth or water. Using two of the major elements ensured it would merely join the magic present in the world without causing unbalance.

Severus felt a pang of sadness at the idea of killing a proud creature like a dragon. At least, there were none hidden in the school.