(A/N: I make NO promises to update or finish this story. It was started long and is not copy and past from a site I used to be on.)
It is funny how one decision can change the course of the entire history of the world. One small seemingly insignificant choice can change everything; change the world as we know it. It seems to reason that the change in one decision would only alter the course of that one person's life when in reality it can change the course of many lives. This decision that changes the course of destiny was Snape's. It is known that Snape choose to call Lily a mudblood and this rightly caused the end of their friendship. This choice did not change, he still called Lily a mudblood but his actions one year after the event changed history.
When Snape called Lily a mudblood, it ruined their friendship not so much because of the foul word he used but because his choice of words caused Lily to realize the truth of the matter. Snape used that word on accident that can't be denied but it caused Lily to realize that Snape was lost that he was too into the dark side, a path he was choosing to follow that she could not. She knew he didn't mean it when it came to her but it was too late. This was why Lily choose to date James Potter. She agreed not so much out of newly developed feelings for him but as a way to show how much Snape had made his choice and she hers. It was also a desperate hope that by dating James, Severus would not stand for it and change for the better. It seemed her plans were for naught though she kept with James.
This is where Snape's choice came into play. At lunch one day that seemed to hold no particular significance things went along as usual. Each house was at their table partaking of the midday meal, there Lily sat with James as had become customary. His arm was slung around her shoulder as he regaled her, with the help of Sirius, one of their more entertaining expeditions through Muggle London.
"There he was chasing us and we figured we'd throw him a bone!" laughed James as he causally ran his hand through his hair to give it that perpetual wind swept look.
"I wanted to just gun it and cause Mary Anne to fly and just look back to see the expression on the poor blighters face as he saw a flying motorcycle!" offered Sirius with a regular cocky grin.
"Which would have been nowhere near as fun as what we actually did!" cut in James as he continued the story.
While this was occurring at the Gryffindor table a different scene was happening at the Slytherin table. Snape sat where he could just see Lily without being obvious. He was at the end of the group that sat there almost like he was a tagalong the boy permitted to be there because he happened to drop the mudblood Evans and had a brain that could be 'useful'. Additionally, Rosier oddly stood up for him and said that he was good and the others went along with it. The topic of blood purity had come to the table and Severus kept his head down and mouth shut per his usual. His long dark hair shrouded his face as he pushed the contents of his plate idly around. He could never speak up in a situation like the one before him as he was only halfblood something the rest of the table graciously over looked.
"The worst of them all is that filthy mudblood bitch Lily…" at the double insult of Lily from Evan Rosier Snape's head snapped up and in that moment he made a snap decision, the one that changed the course of history.
"Don't," he said levelly not looking Rosier in the eye. Severus sat perfectly still something in him boiling now that he had spoken.
Evan Rosier let out a chuckle, "Poor guy, he can't bear to hear about the mudblood because she is just that stupid. I don't blame…"
"Stop it Evan, just stop it!" came Severus' response louder than it should have been causing a bit of a scene, everyone at the Slytherin table seemed to stare at Severus and the conversation he was having with Rosier.
"Are you actually standing up for that mudblood bit…" at those words from Evan yet once more insulting Lily was the final straw, for Severus Snape snapped, he abruptly stood up purposefully taking his side of the table with him causing it to tilt and knock over onto those across from him, which did include Evan.
Over at the Gryffindor table James had finally gotten to the punch line of his joke and story. "Elvendork is both boy and girl!" Peter laughed at the story obligingly as that was expected of him, as Sirius was ready to conclude the story on how the officer reacted to said statement, tears of mirth in his eyes, but he never got to speak as Snape suddenly spoke up shouting for the whole Great Hall to hear.
"I said to stop it! To shut your damn mouth and quit talking about Lily Evans that way! You think you are better than her and can walk all over her! You're wrong! She's ten times more than any of you will ever be! You can't pretend to be anything close to what she is. So just shut the hell up!"
Severus hadn't meant to shout as he did but it couldn't be helped, he was tired of how they spoke about people that were better than them as if they were lower than the dirt, particularly when it involved Lily. He breathed heavily as he came to his senses realizing that the whole Great Hall had grown silent and all eyes were on him. What had he done? He'd signed his own death papers is what he had done, and when he caught a glimpse of Lily's eyes on him, Potter's arm around her, Severus couldn't take it anymore he had to leave had to get out. He didn't want to see the looks on other people's faces, how the shock registered with them, how the Syltherins were going to take him out, not even how the Professors were going to deal with what happened. He turned and he ran barely keeping his eyes up enough to see a few steps in front of himself.
"Well that was interesting," tried to joke James as he turned back from the scene that Snape had created attempting to guide Lily with him but Lily wouldn't follow.
"I have to go," spoke Lily briskly getting up from the table leaving James sitting there hanging with no girlfriend at his side. Shock seemed to register on his face but Lily didn't see it, her focus was on the slightly hunched black figure that was fleeing the Great Hall.
"Severus!" she called once in the Entrance Hall, the Great Hall doors closed behind her but, her voice seemed to fall on deaf ears as Severus's figure continued to retreat away. Lily picked up her pace and followed the Slytherin boy out of the castle into the slightly cool air, the sign of the seasons change.
Once on the steps outside the castle Severus stopped. Head bowed the events of just moments prior racing through his mind and the different ways the Slytherins would ensure his death that night. He only hoped it would be swift because he didn't know if he could bare to look at Lily after what he had just said and done.
"Severus," called Lily her pace slowing down as she reached out to touch his shoulder. It caused him to tense as he realized she had followed him. With eyes cast to the ground not looking the girl in the eyes, figuring she was furious with him, he began to apologize for his actions. Once the whole apology left his lips he waited for Lily to still yell at him for what he did, but she didn't, instead he was met with kind words.
"Did you mean it?" asked Lily trying to search his shrouded eyes. The surprise hit Severus very hard and he ventured to look up at her.
"I meant every word, Lily," he spoke honestly because he could be nothing else with her. "How could I not? I've practically loved you since the first day we met. I would do anything for you. I know..." but Severus never got to finish his statement as Lily pressed her lips against his.
Lily had always had feelings for Severus and she had kept them at bay as she watched him start down a path that she could not follow, she stayed with him through thick and thin in hopes that one day he would realize what he was doing wrong, thus when Severus called her a mudblood at the end of fifth year Lily thought all was lost, it was why no apology he made that night had worked. Her heart had broken that night, but after what Severus just did she knew that he had walked away from all that he had once clung to and that was enough for Lily.
It is from that one moment in time that things changed, Lily and Severus were once more inseparable to the point that they got married, causing the one most know as 'the boy who lived' not to exist and a new "chosen one" was selected, this is his story, the story of how the world changed based on one small seemingly insignificant choice.