Welcome to THE UNBREAKABLE VOW! This story will be a novel-length fic, featuring Severus Snape and Lily Evans Potter as a ship AND will also become a Severitus fic, featuring Snape as Harry's father.

In this fic, there will be a lot of mature themes, though not necessarily explicit. Currently, as this story is rated T(een Audiences and Up), but there is a clear demarcation where the story will increase to an M(ature) rating, so be forewarned. I will make it clear which chapter marks the rating increase, so there is a heads-up.

While this is a romance between Snape and Lily, unlike most shippers, I will not be glossing over the very disturbing aspects of their friendship and potential shipping - especially the behavior of Snape and what it means that this is his behavior. The very real issues of prejudice and bullying and war will be address in this fic and nothing will be sugarcoated, as best I can. If you have concerns about how a ship like this can be in character but still get Snape and Lily to a place where they're a healthy ship? Well, that's the plan in this story.

I have had a very complex relationship with the Snape and Lily ship since 2007 and with this fic, I plan on tackling how it can be touching and disturbing at the same time and how JKR meant that Snape had to change in order to be someone Lily could love and love for real.

There are three parts to this story: Part I, which takes place during the final two years of Snape and Lily's Hogwarts years; Part II, which takes place in the two years after Hogwarts before Harry is born; and Part III, which takes place from Harry's birth to Halloween 1981 and a bit thereafter. Harry is a character in this story, but for obvious reasons, he doesn't appear until Part II - which means there's going to be a great part of this story that doesn't feature Harry. His character listing is not a fraud or mistake, it just takes a while to get there. Be warned!

Without further ado, let's get started on my first attempt at Snape/Lily fic and Severitus - THE UNBREAKABLE VOW.


The Mending
1976 - 1978

CHAPTER I: Penance and Crossroads

Friday, 25 June 1976

"Snape is outside in the corridor and so far, Fabian has taken forty points from Slytherin, because he refuses to leave."

"Fabian can take as many points as he likes off of Slytherin. Into the negative, for all I care. Leave me alone, Mary."

"Lily! Come on, now - something must be done about this. This is unacceptable!"

"I didn't tell him to come here! Not after he - after he - "

"You may not have told him to come up here, but you're the reason why he is lurking in the corridor and is refusing to leave. Lily, you have to deal with your little friend. I'm not only asking you as a friend, I'm asking you as a prefect, too."

Lily sniffed discreetly, hoping that Mary wouldn't hear, that she'd continue to be so indignant at having to talk through the bed curtains that the older witch wouldn't notice that she was actually crying. She hated that she couldn't stop crying or that the ache in her chest was so acute, it was painful. More than anything, she hated that the reason she was secluded in her bed in Gryffindor Tower with a broken heart and an endless wellspring of tears was the one person she loved more than anything -

And the person who'd hurt her so gravely, earlier this afternoon.

The person who Mary was now demanding that she come down from the dormitory and deal with.

"How long has he been out there?" asked Lily, wiping away her tears with a trembling hand.

"All bloody afternoon! He hasn't left since after Fabian broke up the little tussle between him and the Mauraders down by the Black Lake - and, frankly, it is getting to be a little unsettling."

Lily looked up sharply. All afternoon? Severus had been in the corridor all afternoon, this entire time she'd been up here sobbing and feeling the pain of a splintered heart - and he hadn't left, not once? Lily sniffled once more, a wild spark of hope budding beneath the continuous ache of humiliation and hurt.

If Severus had been waiting all afternoon and all evening outside the portrait hole, he had clearly and obviously been waiting for her. Waiting to see her or for her to come from within Gryffindor Tower so that he could talk to her. Surely, his insistence on speaking with her meant that he wanted to apologize, that he had an explanation?

But, Lily couldn't let herself get attached to such a hope.

Severus had done something unthinkable and reprehensible, earlier this afternoon after their OWL examination had concluded. Not only had he wounded her deeply by calling her the hated, poisonous slur that never failed to make her feel inferior and less than human - he had done so publicly, in front of a crowd of their classmates.

Lily wasn't sure what was worse: the pain of being called Mudblood by Severus or the humiliation of having everyone see and witness her friendship and her love for Severus so cruelly thrown back in her face.

There was truly no telling what Severus wanted now, what motives or designs he had by waiting in the corridor with an unyielding intensity, unsettling her fellow Gryffindors and putting himself at risk for an assured aggression, as a Slytherin in enemy territory.

The only way to know was to go down to the portrait hole and find out - and face Severus directly, after the hellish and unthinkable moment they'd had earlier, by the Black Lake.

"He really won't leave until he talks to me?" Lily asked of Mary, as she reached for her wand and prepared to refresh her swollen, blotchy, saddened face with the necessary charms. "And he's been out there all afternoon and all evening?"

"Snape threatened to sleep in the corridor, Lily. You have to do something about him - or, I can't promise that nobody else will."

Lily dissolved the solidly cast privacy spells that she'd put upon her bed curtains after bursting into the dormitory, sobbing and shaken, earlier that afternoon. Mary was standing impatiently, her hands fiddling with her wand anxiously. She appeared relieved to see Lily getting out of her bed, pulling on a dressing robe with a determined expression on her face.

"I'm going to go down and talk to him, Mary. I promise, I'll take care of this situation - because it is a problem between Severus and I, not Gryffindor House."

Mary nodded encouragingly. The sixth-year witch motioned her to go ahead, with haste. "There's the Lily I know! I'm not sure what happened, but I'm sure everything will work out for the best."

Lily hoped so, herself. She couldn't be sure, however. As she walked down the staircase and into the Common Room, which held only a handful of Gryffindors in the late hours after curfew, Lily hoped that everything would work out for the best and there was something that could be done to heal and move past the awful crossroads that she and Severus found themselves at.

She couldn't be sure of it, however, despite her hope.

After all, she had been sure that she was in love with Severus and he knew this as surely as he knew they were best friends. But, after the events of this afternoon, Lily couldn't be sure of anything, let alone whether or not Severus returned the love she knew she had in her heart for him.

Briefly, Lily paused, before pushing open the portrait hole door and preparing herself to be faced with the person she loved and hated the most, in this very moment.

"Severus. Mary told me you were threatening to sleep out here, if I didn't come down to talk to you - so, what it is? What could you possibly have to say to me?"

Severus couldn't feel his legs, as he stared at Lily - a thousand emotions roaring through him with an intensity he'd never known before.

What did he have to say to her? What could he say, after the awful and unspeakable mistake he'd made earlier, in anger and humiliation for what was being done to him and by whom? What words were there to repair the chasm that calling her Mudblood had created, in one scandalous and regrettable moment?

"Lily." Severus said, her name both a sacrament and a penance. "Lily, I'm - I'm so sorry."

Lily blinked at him coolly. Her stunning eyes were as hard as gemstones, nothing of the warm and loving and spirited girl he loved so fiercely, in her emerald and jade eyes.

"That's all? You're sorry?"

Severus swallowed, thickly. "I don't know what to say. I don't know what I can say to make this better."

Lily made a noise of disbelief. "What makes you think that this can be made better, Severus? You called me Mudblood! You called me Mudblood in front of everyone, as loudly and sincerely as you could - and, you think that this is something that can be made better? How dare you?!"

Severus was ashamed of himself down to his bones, as Lily's voice broke off into a wounded sob, and for the first time in memory, he watched as she began to cry.

Lily had been his best friend since they were nine years old, the only other soul he'd ever known in the dull and miserable village of Cokeworth that was like himself or worthy of his time and attention. The Evans family had moved to Cokeworth in the spring of 1969, when Mr. Evans had purchased the old mill and turned into a factory, and if it hadn't been for that chance moment of seeing her on the playground and witnessing the unthinkable wealth of power Lily possessed, as small and young as they were then...Severus would not have ever come to know and befriend the treasure that was Lily Evans.

Their meeting had been pure chance, perhaps a bit clumsy and awkward as he had never had a friend before Lily and never wanted one until her. But, the connection had been instant, sincere, and powerful - unbreakable, if he allowed his heart to speak instead of his mind and his logic.

In their seven years of friendship, so far, Severus had seen the full and beautiful spectrum of Lily and the zeal and zest in which she lived life. Not once, however, had he ever been witness to this.

Lily was in pain, as she stood here, quietly sobbing into her trembling hands. Lily was hurting and wounded, betrayed and overwhelmed -

And, it was because of him.

Severus felt an ache in his own chest, an ache of shame and guilt and no small amount of self-loathing, as this awful and sour epiphany crushed him under its bitter weight.

Severus had never seen Lily cry and it was because of him that he was now bearing witness to the unseen.

"Perhaps I can't make this right," Severus murmured to himself, stepping back heavily, his dark eyes unable to look away from his weeping Lily. "I've done something horrible and unforgivable and maybe...maybe I have really done it, this time. I've finally driven you away."

Lily looked up, defiantly. "So, that's it? You aren't even going to try and fight for our friendship? I must truly be the Mudblood you think I am, if you're giving up on me this easily, Snape."

Severus recoiled as if she'd physically struck him. "Of course not! I'd never give up on you, Lily. I'd never - you aren't -" Severus leaned against the wall he'd steadily been backing up towards, sliding down against the cool stones helplessly until he was in a pathetic crouch. "All I know is that I made a terrible mistake earlier today and despite what I said, I don't think of you as a - as a - I don't think of you as anything less a powerful Muggleborn witch, my best friend - my only friend! If I could do anything to take back what happened, I would, in an instant. But, I know I can't. I can't take it back. So, what do I do, now that I can't take it back? What can I do to make this right, even though I can't take it back?"

Lily sniffled, discreetly, as she wiped at her tears and gathered herself. There was a ringing silence, as Lily crossed the corridor to be on the same side as he was - and, sat down neatly beside him, a meter or two away, but still alongside him, nonetheless.

"You can't take back what you did, but what if I told you that only if you wanted to, there is something that can be done to fix this?"

A spark of wild hope flared to life within him, a hope that Severus knew he didn't deserve, as her words hung in the air between them.

Lily was making it clear that they were standing at a crossroads and the choice of what path would be followed next was entirely his.

Severus had never given someone his undivided and true attention as he was giving Lily in this moment, as he held in breath in quiet fear and anticipation, and listened to whatever mercy that Lily was offering him.

Lily gathered her thoughts, as Severus waited with the patience of a monk for her next words.

While conventional wisdom and logic would say that this conversation should be happening and she should have sent him away from the second that she stepped from the portrait hole, Lily wasn't interested in either of those approaches. What mattered here and what mattered now is that there was a chance for forgiveness and a chance to start over again - and, if she never offered it, Lily wasn't sure if she would be able to be at peace with such a decision.

Severus was the first person she'd ever known that had her special and overwhelmingly powerful gift. The gift she had come to be taught was Magic. Dad had been cautious but curious about her unnatural, uncontrollable abilities and Mum had been afraid, her steady and reasonable mind unable to fathom that she'd given birth to a child that was so - unusual. A child that was a witch and nothing like any of the rest of their family. When Petunia had scorned her for her gift, a bitter envy turning her against Lily instead of bringing her closer when Lily needed her the most, Severus had been there to welcome her and her magic. Severus had been the only one who knew what it felt like to have the power of Magic thrumming throughout your entire body, ready to be given shape and form, ready to connect and be nourished by Mother Magic.

Severus had been the first person to give her books from the Wizarding World and allowed her to borrow them from his mother's personal library, as fast as she could read them.

Severus had been the one to explain to her how the Wizarding World worked, sharing knowledge and history about Wizarding Britain, how there were wizarding folks every where on the planet, and how there was a rich and complex world of Magic and all its might, waiting for her as a witch.

Severus had been the only true friend she'd had, growing up in the new town of Cokeworth, and filling those two awkward years with a friendship and a companionship she may have very well suffered without, until reaching Hogwarts at eleven.

Severus had been her first friend and her truest companion, sharing the gift of Magic and encouraging her power and her might as a witch, as nobody had before or since. Severus was the one who knew her when she only thought she was a Muggle, had stood beside her solidly as she learned what it meant to be a witch and convinced her parents of the validity of it, and he had been the most central part of her development into the powerful witch was growing into, daily.

One moment had threatened the truth of all of that. One moment had been enough to bring them this crossroads where she was about to lay out the choice that would be a defining point in their lives, she was sure of. One moment was all it had taken to fracture their friendship and put them on the precipe that they were on now.

Could one moment be enough to fix it, as well?

"I don't want you to see this as an ultimatum nor do I want you to force yourself to do anything you don't want to do," Lily began, quietly. "You are my best friend. My very best friend. I have other best friends, like Marlene and Dorcas - but, you're different, Sev, you always have been. I have best friends and I have friends and all of them are wonderful, I truly and deeply enjoy my friendships. Yet, nothing has compared to my friendship with you. I could lose Marlene or Dorcas as best friends and I would be upset, but I don't believe I would hurt like I am hurting now. I could not continue being friends with many of my other friends, like Mary, I guess, for example. If I were to not be friends with you, however...I'm not sure I would be happy with that. I would feel like a very important part of me was missing."

Severus was staring at her with all the inner parts of his soul upon his face, it seemed. Lily had never seen an expression from him like this before and it smoldering with the edges of something deeper, something warmer - something that made Severus appear to be more of a man than he was a boy, in that moment.

Lily tried not to flush under the intensity of his gaze, determined to make it clear what she held on her heart and what should happen next.

"You're my best friend, Severus, the most important person to me - but I cannot continue being your friend and you will not continue holding that place of importance in my life, if you don't change and change now."

Severus didn't so much as blink. "Tell me. Tell me what I have to do so that I can keep being the most important person in your life and I swear on magic, Lily - I'll do it!"

Lily looked at him searchingly. This was the moment of truth, the moment when she'd discover how much she truly meant to Severus and if his henious actions earlier were something that could be forgiven and healed, a wound they could move past and leave in the past.

"If we're to continue being best friends and if this friendship is to grow and evolve, Severus, then you must leave Malefic Magic alone."

There it was. The true worry and fear that Lily had been harboring, with every passing year and every year they got closer to the end of their schooling. Malefic Magic was dark and aggressive and meant to make its users the vessels for the wild, untamed, and uncontrollable magics that did harm and corroded one's magical core with malice. Malefic Magic was the darkest of Magics, the extreme of Peregrine Magic, and the opposite of Benevolent Magic.

Severus had been caught up in the ensnaring enchantment of Malefic Magic and was headed down a dangerous path -

And all Lily was asking to salvage their friendship was that he would renounce it and travel down that spiral no more.

Severus had an unreadable expression on his face, even as Lily reached over and grasped one of his hands, fiercely.

"I understand the study of it and the use of it academically or perhaps, even to protect yourself. But, Severus - what you're doing with Malefic Magic? It isn't any of that and you can't deny it. What you've gotten tangle up in and is corrupting you is the worship of Malefic Magic and all its influences and I don't like that. I don't like the friends that Malefic Magic is bringing you nor how it is has changed your temperment and begun twisting your minds. Your perception is warped, your morals are slipping - Severus, even your language is changing and there is no greater proof than today!"

Severus appeared to have been turned into stone at her words, only the harsh bob of his throat indicating that he was still listening and hearing her impassioned plea.

"Severus, my life wouldn't be the same if you weren't in it, but I don't want you if the you I have is going to be corrupted and twisted by Dark Magic - by Malefic Magic. The Severus who is a devoted practitioner of Malefic Magic is not the Severus I know nor is he the Severus I love."

Lily surprised herself with her boldness, her admission of what she didn't think her Gryffindor heart would ever be brave enough to declare - but, there is was. Severus blinked wildly, the declaration breaking him from his stony countenance, and revealing a rawness of emotion that made him grip her hand back, with twice as much force.

"The Severus that you love?"

Lily ignored the exposed and unsure feeling that came with freely discussing her most treasure and securely held secret, the secret that she'd been nursing since last summer.

"Yes." Lily said, simply. "I love you, Severus. As my friend, yes - but, as something more, I believe, as well."

It was as if the world was suddenly righted and he could see clearly, after an undetermined time submerged in a fog.

Severus marveled in the slender hand held in his, the perfect fit within his own large and thin-fingered hand - perfection in the shared scars and nicks from potioneering and the smooth, supple feel of the moisturizing salve she'd created herself. Lily allowing her hand to rest so comfortably in his was perfection, especially, for she had reached for him first and offered more than simply her touch.

Lily was in love with him.

From her own mouth and not his most hidden, wildest fantasies, Lily was in love with him and it was this love that had her sitting beside him in this deserted corridor, making it clear that there was only one forward path if her love was to be given freely and honored.

"The ultimatum you're giving me - "

"Not an ultimatum, Sev. A choice. I'm giving you a choice and because I love you, I'm trusting you to make the right choice."

Severus considered this gravely.

"Very well. You're giving me the choice between abandoning Malefic Magic and all its ideals, as well as the friends and the influence that comes with it...or abandoning our friendship, if I'm to stay devoted and become a practitioner of it?"

Lily nodded, resolutely. "It's either Malefic Magic or me, Severus. There is no other option. I love you but I won't love a wizard who is devoted to Magic like that. Not even if that wizard is you."

Her words were clear and left no room for discussion or reasoning or negotiation. His forward path was clear, if he were to keep Lily as his friend and discover what it meant to have her love. There was no room in his life for Lily and his obsession with the intoxicatingly powerful magic he'd felt was his only solace, so far - and, standing at the crossroads of this choice, with Lily staring at him expectantly, Severus understood that there was only one choice that was the right choice.

"I choose you, Lily. I choose you over Malefic Magic and if I have to sacrifice all of that to be with you - then, you are what I choose, always."

The Sun itself could not rival the brilliance of the light of hope and relief that shone within the emerald and clover depths of the eyes he so loved, the eyes of Lily. The light, Severus realized with a distant shock of disbelief, was the love that she had so boldly declared that she had for him and him alone.

Severus would do anything to keep that light alive and glowing within Lily. Anything at all. Therefore, it wasn't difficult or something he had to dwell on, when he asked the following question, the question that what truly put him on the path he would travel, from this point their crossroads.

"What do I have to do to earn your forgiveness, Lily? What is it that you want from me, that will fix this and show you that I apologize - that I'm ready to change, as you want me to."

Lily smiled, gently, delighting Severus in the softness and the tenderness that was held for him.

"If you want to earn my forgiveness and if you want to see this healed, is what I want to see and what I need from you..."

[AUTHOR'S NOTE: This chapter was influenced by "The Prince's Tale", Chapter 33 of Harry Potter and the Deathly Hallows, but there is no direct text lifted from this passage. Everything in this chapter is merely an allusion to that passage, in canon.

Clearly, I've put my own spin on how the conversation after the incident at the Black Lake could have gone, if there was the mind for a different direction. As this story is a Romance, everything will start to pick up speed in the first few chapters - but, be warned of the subgenre of this story, which is Hurt-Comfort, and that despite what this story may suggest, there WILL BE a canon ending.

Yes, Godric's Hollow still happens, Voldemort still murders the Potters, and Harry still becomes the Boy Who Lived - but, where does Severus fit in and how is this a Severitus? That is the question!

Reviews are welcome! Onwards to the next chapter of our tale...]

[Edited/Revised: Dec. 2019]