A/N: Thanks for the follows, favourites and reviews. This chapter is mainly a backstory of Severus' past.

On the afternoon after Harry's first potions lesson Severus took a portkey back to his lowly house at Spinner's End and began to search through his belongings. He was trying to find the photo of his first year cohort at Hogwarts. He was particularly interested to see whether Harry looked more like him or Sirius Black at his age. Not that it proved paternity but it was a start.

With the amount of mess that was spread around his house it would take a while to find anything, even with the assistance of magic. He used a variety of household spells to try and sort out the junk that was lying around. Over the years he had forgotten where his mother had kept her most valuable belongings safe from her husband. While he was growing up, his mother hid things to save them from being broken or hocked by Tobias Snape.

He suddenly became amused by the fact that although he hadn't spent much time in the house since he was sixteen; the house was in a state of utter chaos. In fact, the house had been fallow since he was a teenager.

"I don't know why I still keep this place," Severus muttered with vile bitterness, "It's not like I have any happy childhood memories here. I should have sold it to muggles ages ago."

It was true; Severus completely resented this house more than anything else in his life. It was where his parents constantly fought each other and where he was abused as a child.

His mother had never laid a harsh hand on 'her little man' but Tobias Snape on the other hand was a brute to both of them. Severus would remember when he would come back from work drunk in a foul mood and start yelling at both of them; his violence would then escalate to throwing a young Severus against the dull brick walls of the house or do something equally horrible. He remembered his mother was always there with a healing potion and a warm hug afterwards. Although she was able to cure his wounds, over time he had developed a spidery walk because of the repeated injuries. It was his mother who taught him how to brew potions and magic before starting Hogwarts.

Severus found himself shaking his head. Why did his wonderful, intelligent mother end up marrying a horrible muggle like Tobias Snape? Until he was fifteen this was a great mystery.

He did know that his mother had a life just as difficult as his own. Eileen Prince was born into a pureblood but dysfunctional family and was bullied for most of her time at Hogwarts, mainly by Gryffindor students. Once she had left Hogwarts she found a job in the ministry as an Unspeakable and through this, became involved with a wizard who her pureblood supremacist parents didn't approve of. She couldn't run away with him because he was older and already married with other children of his own. He was also in a position of power and could not afford to have the knowledge of fathering an illegitimate child to a much younger woman going around.

So she married Tobias Snape, the first muggle man she could find and addled with his memory to make him believe that he was the father of her child. Unluckily, he turned out to be a brute. This was all written in a note that his mother had addressed to him before her death but he had known that Tobias Snape was not his real father since he was twelve.

He remembered the night with perfect clarity. It was the school holidays and he had stayed up late revising school work because he couldn't get to sleep with his parents fighting. After the argument had finished, his mother ran into his room sobbing with her face buried in her hands. There was blood seeping slightly from in between her fingers and ran down the back of her palms. She then told him between sobs:

"I'm sorry Sev," She said, "Tobias isn't your real father. I'm sorry that I've lied to you for all these years. I hope you can forgive me."

He said nothing, but let her cry herself to sleep next to him. His twelve year old self knew that he was meant to feel angry at her but he didn't. Instead, he felt relief – he wasn't connected to the man by blood at all. After that Severus started referring to himself as 'the Half-Blood Prince' in an attempt to distance himself from Tobias Snape as much as he could. He had never bothered to change his name or tried to find his biological father because as far as he was concerned, the man was irrelevant to his life. Besides, there would be no way to track the man down – all he really knew was that the man was successful within the ministry and was married with other children. Quite a few wizards would have fit that description during the decade he was born.

If he was Harry's father, he was determined to be a much better man than both his father by nature and his legally-father Tobias Snape.

After all these years, he still had so many unanswered questions for his mother. Why did she stay married to him when he was such a bully? Severus supposed that she didn't believe that a decent man would come along and love her. But why didn't she use spells to modify his behaviour? Also, why did she isolate herself away from the magical community? With the only exception being her adult gobstone club. Who was she so afraid of? She might have been ashamed to have a child with no father but that didn't explain why she didn't even set a foot in Diagon Alley.

As he continued to clean his way through the house, he made his way closer and closer towards his mother's room. He hadn't been in the room since he was fifteen, but knew that there was every possibility that the place was where she would have kept photos. The last time he had been in there was to remove his mother's body.

Severus was finding it harder and harder to breathe. He had a vivid flashback of when he found his mother dead. He can come home for Christmas that year knowing that she had been feeling more miserable than usual and that his stepfather's abuse was becoming more violent since he had been involved with another woman. He opened the bedroom door expecting to find her reading in bed but instead found her pale body lying there silent and still. There was a note next to her bed and empty bottle of poison beside her. He didn't quite remember what happened afterwards but remembered starting to scream and cry wildly. He had completely lost control of his magic and emotions. The next thing he could remember was sitting in a destroyed living room, there was glass and torn wallpaper everywhere. Not to mention smashed furniture.

After that he was an orphan, as Tobias Snape had disappeared afterwards. Shortly after Tobias had come home to find that Severus had discovered her dead, they had gotten into their final fight and this time, Severus used magic. Severus didn't care where the man had gone. He was only glad that he wasn't coming back.

His mother's room was exactly as she had left it after all these years only dustier. Severus didn't need to look very far because his mother had kept a picture of himself as a child on her bedside table. He blew off the dust to get a better look.

"My goodness," Severus muttered in shock, "The boy looks just like me."

It was true. Harry Evans was nearly a twin of himself at around that age, although he didn't have dark eyes or a hooked nose. Harry also looked like he was a lot cleaner as well – mainly because unlike him, Harry was probably taught how to look after himself.

Severus didn't know what to do. Of course, he wanted to be a better father to Harry than what his own father had been but he knew that claiming Harry as his own would be detrimental to his plan with Dumbledore. Besides, he knew how the conversation between them would end even before he had started it:

"He's my son, Albus."

"Severus, you can't just tell the boy. You are supposed to be a spy. If you really loved the boy and his mother you would protect him from a distance. A war is coming; Severus and you know that both Harry and yourself will be at the core of it. We must all do what is right, I'm sorry."

The crafty old man had probably known this all along. He would have, he knew Lily well as she had been a part of the Order since she had left school.

Severus left his house at Spinner's End and went to The Leaky Cauldron to get something to eat. He didn't want to go back to Hogwarts just yet.

However, there was one particular way to definitively prove that Harry was his son, the Demiurge potion. Easy as anything to make, but the problem would be getting some of Harry's hair without anyone noticing.