AN: This is one of my theories as to what happened on that Halloween night, when Harry's parents were killed.

As the smoke rose high above Godrics Hollow, Severus Snape was slumped upon an old Willow, mourning the death of his true love.

Lily potter

They had known each other since their first year at Hogwarts, she had been his only 'true' friend, and although they had been divided into opposite houses at 11, Severus and Lily grew closer every year.

The greasy, black-haired Slytherin, with his hooked nose and pallid skin courting the red-haired beauty of Gryffindor, with her dazzling smile and sparkling green eyes would have broken all of the rules that the wizarding students held in high regard.

So, in true house fashion, the Slytherin proved just how sly he was, whilst the Gryffindor proved her stubbornness.

They dated in secret, until that fateful summer day in their fifth year, when Lily's 'friends' attacked Severus.

Despite their agreement to avoid each other infront of their houses, Lily had defended him, and in return, Severus had hissed three words in reply. 'Filthy Little Mudblood'.

The very memory of that day, loosing Lily, brought a fresh wave of despair upon Severus. He brought a shaking hand to his face, in a vain attempt to stem the tears flowing freely from his obsidian eyes.

His companion, his equal, his friend…his love. She had barely spoken a word to him for three years after that mistake – the biggest mistake of his life…worse that his joining the ranks of Voldemort.

Apart from the usual reasons for joining the Death Eaters, Severus had conceded due to another reason. 'Join and the Mudblood will be spared'. And although they had not spoken since their OWL's, Severus knew what he must do – he pledged his allegiance, and took the Dark Mark.

And to all accounts, he was one of the most talented, and loyal Death Eaters; sly, calculating, and always carried out his 'jobs' with an air of detachment about him.

However, when Severus learned of Lily's engagement to Potter, he found himself at their home, pleading with her to reconsider. He apologized for his thoughtless remark, and told her of his undying love, and, for a brief, wonderful moment, Severus thought that she might reconsider. The green eyes sparkled and an uncertain smile played across her rosy lips – an image of her that would be remembered by Severus until he died.

Just when it looked like he could be truly happy, James came to the door. Though they weren't aware of it in their early school days, subconsciously, they both knew that they wanted the same women, and this was most likely were their problems had started.

Now, they were no longer young boys, but men, and the power of 'wanting' was stronger.

Placing his hand on her shoulder, James had tried to lead Lily away from the door, and that was when Severus had made another abysmal mistake. He told Lily of his sacrifice to spare her life…and had earned himself a slap, along with, 'How could you! Why kill all those people for the sake of my life? What makes me so special? Why should I be spared Severus? Why?'

A moments silence before Severus replied, 'Because I love you.'

Shaking his head, trying to compose himself, Severus gasped as Ministry wizards began to arrive, no doubt aurors and forensics. How they could possibly confuse who the murderer was, was beyond Severus, as the Dark Mark hovered ominously over the small, burning village.

Thinking back to the last time he talked to Lily, Severus felt self-loathing well up in him. It had been her wedding day – supposedly the happiest day in any young woman's life, not for Lily.

Severus new why she had finally settled for James over him. How could an Order member be married to a Death Eater? – The same reasons why a Gryffindor and Slytherin can't be married added Severus bitterly.

A clash of opinions, opposing views, one self-preserving, the other mindful of others. It was like black and white, there was no middle ground, no 'grey'.

You were either both Gryffindor or both Slytherin. Both Order Members, or both Death Eaters. Either 'Good' or both 'Bad'.

Unfortunately for Severus, the 'Happy Couple' were Gryffindor, both were Order Members and both were 'Good'.

Severus remembered Lily, with her flaming hair fluttering in the faint autumn breeze. She had chosen an emerald dress with gold trimmings, adorned with ancient runes of protection and luck. Her friends had been told that the colour had been picked because green matched her eyes. Severus, on the other hand, had an unwavering suspicion that she had chosen the colour to be close to him on her wedding day. Lily had never expected to see him there.

Severus had come to see her one last time, to assure himself of her final decision.

After her initial shock, Lily remained firm in her choice of a husband, and, as Severus turned to leave, she had offered him a place in the Order, and Dumbledore's protection.

Why he didn't listen then, Severus would never know. All he remembered of their exchange was an argument about his sacrifice. Why couldn't she see what he had done for her? – Given his freedom to the Dark Lord in exchange for her life.

At some point in the heated conversation, Severus had ripped off his grey cravat, and, seeing Potter striding over, threw the material to the ground, storming through the crowd.

From where he was now standing, Severus could see Prophet Reporters apparating and taking photos of the green mist that had, less than an hour ago, been the Dark Mark.

A Dark Mark which he had produced.

Severus' mind ran through the last two hours of his life. A life which now had only one purpose, and which could be stifled in the very near future.

He remembered how he had been taken to an unknown location, via Portkey at his Masters' request, had stationed himself on this very hillside overlooking the small, surrounding village, and had cast the Dark Mark upon seeing the first flash of green light.

The Serpent and Skull had thrown a green shroud over the houses, illuminating each one, and it was at this moment when Severus realized where he was. Godrics Hollow.

Hoping that he wasn't already too late, and ignoring any thoughts of sparing his own life, Severus sprinted towards Lilys' house.

The door was blasted open, revealing the cream coloured walls of the hallway, and the unwelcome sight of blood on the carpet.

Ignoring the pumping sound of his heart, Severus strode through to the living room, disgusted at his own happiness that it was not Lily who had been killed, but Potter. But that meant that she was still alive somewhere in the house.

Severus muted his breathing and listened for any sound of movement. All around him was silence, except for the heavy ticking of the Grandfather clock in the corner of the room.

Suddenly, a raised voice from above saw Severus making for the stairs.

He had promised that she wouldn't be hurt! But promises could be broken.

As Severus barreled up the last few steps, he wondered if the Unbreakable Vow might stop the Dark Lord from killing the one he loved, but as he reached the doorway to little Harry's bedroom, Severus was greeted with his answer.

A pair of dazzling green eyes met his, filled with sorrow as they were covered with a curtain of green light, and extinguished by the cruel hand of death.

Severus barely heard himself screaming through the myriad of sound surrounding him.

The Dark Lord laughing, Lilys' son crying, Lilys' scream muffled by the evil spell.

For all of his gloating and constant sneering about the ways in which he had gone to secure immortality, for a moment it looked like Voldemort had been speaking the truth.

He was in for a shock.

Severus stepped more fully into the room as he saw his master turn towards the squealing child. And for the wildest of moments, Severus remembered a piece of text that he had read in his Grandfathers' library. Placing all of his hopes on a 1000 year old spell, Severus backed up against the bedroom wall, and begged for forgiveness, looking into Lilys glassy eyes, as a wand was raised, and a final flash of green filled the room.

Seconds of silence passed with Severus unwilling to look at the scene before him. It was only when a small hiccup sounded that he dared to breathe.

'Thank you'. He whispered silently to the hollow room.

Another hiccup sounded as Severus looked about him and saw the pile pf robes that had previously been his master and a small bundle of blankets containing a baby.

Stumbling over broken toys, Severus peered down at the baby boy which should have been his son and was greeted by two sparkling green eyes.

'You have your mothers' eyes you know?' he whispered, as a tear trickled down his nose. The baby made a small noise as he was lifted off the bed.

Staring down at the bundle, which was now in his arms, Severus' attention was drawn to a lightening-shaped cut on Harry's forehead. He pulled out his wand, and began to heal it, murmuring the occasional thanks to whatever deity had spared the child's life.

The spell which he had used, whilst not long to cast, required an incantation, which was often mistaken for a song by the untrained ear. Harry had fallen asleep.

Laying the baby back on the bed, and making sure that he couldn't roll off, Severus turned his attention to Lily.

Guilt-ridden, Severus fell to his knees at her side, sobbing freely. He brushed a strand of her hair back from her face, and, after a slight pause, leant forward to close her eyes and plant a kiss on her paling lips.

Throughout her life, she had always possessed a fiery quality, only during their nights together in the potions labs, the library or at the top of the astronomy tower, when she fell asleep in his arms, did she ever look as peaceful as she did now.

'I'll look after him, Lily. I'll do my best,' murmured Severus, trying to memorize her prefect features, knowing that this would be the last time he would see her until he died.

Of course, he had photos', but they would never do her beauty justice. He would have to wait until their next meeting.

Standing up, Severus placed all of the protective spells he knew on Harry, before casting a final glance around the room, and heading back down the stairs.

He had made his peace with Lily, now he had to go to Potter.

Severus stood in the living room doorway for a minute, slowly becoming aware of the time that had already passed. Finally making up his mind, Severus summoned his pride, and walked over to the fallen Gryffindor.

He stood over the body, taking in the injuries. A cut above the left eye, glasses missing - obviously being shattered, his hair as scruffy as ever. A deep gash on the right shoulder, and the familiar glassy eyes.

Leaning down, Severus brushed the eyes down, and set about cleaning the blood. A dead body couldn't repair itself, but the blood could be dissipated.

Once he had finished, Severus sat back, looking over his rival. 'You got that heroic ending you always wanted, Potter…along with the girl.' Severus paused, 'I'll look after your son for you, but I'm only doing it for Lily.' Frowning slightly, Severus added, 'I never said congratulations on the wedding…or the birth….'

Time passed slowly, as a shout sounded outside, alerting Severus to the fact that the Ministry could be here any moment. 'See you around Potter.' Was the last thing that Severus said to James, before sprinting out of the house, to the bottom of the front garden. Once clear of the anti-apparition spells, Severus had apparated to where he stood now, watching over the scene with conflicting emotions. Lily had been killed, so had Potter. But little harry had survived…what did that mean?

And his vow to Lily, about keeping harry safe? Quickly making up his mind, Severus decided to write a letter to Dumbledore, explaining himself, before exposing himself, and being purposely placed in Azkaban, where he could be punished for his mistake all those years ago.

Filthy Little Mudblood

The first mistake of many which had led to Lily's death.

AN: Just like to say that this fic was inspired by my feelings when my mum emigrated to Australia a couple of weeks ago. Halfway through, I decided to change a few things. And Lastly, I decided to wait until it was closer to Valentines Day to post it. I swear, it wasn't supposed to be SO depressing at the end, I guess I just got carried away! Anyway, please R&R!