Disclaimer: I own none of these characters or this world, they belong to J.K.
Summary: Ginny goes to Azkaban for Harry's death in the chamber. The results of this are unexpected, giving rise to a different recipient for the prophecy.
The girl formerly known as Ginevra Molly Weasley sat in the corner of her cell with the scrap of cloth that only the most generous would call a blanket wrapped around her naked body. Merlin, how she despised her body. At fifteen she had blossomed into a quite attractive young woman, which only encouraged the guards to rape her more often. The rapes started the very first night of her permanent stay in Azkaban, and were repeated nightly, each guard rotating so that she saw each of them at least once a month. When she started maturing at thirteen she started seeing a couple of different guards each night, and now at fifteen there were days that she had been raped by every guard on the island in a 24 hours period only for them to start over the next day. Even Fudge took a turn with her when he toured the prison three years ago.
The day Fudge had his way with her was the day she stopped being Ginny. As Fudge left he conveniently forgot to lock the door back, not that anyone needed to worry about her escaping. By this point she was twelve-year old girl whom had suffered a year of repeated abuse, driving her to catatonia to escape the hell her life had become. She even believed that she deserved to be the prison whore by this point, and just accepted her abuse with a blank stare as she lay unmoving with men on top of her. That night no guard visited, the warden feeling that Fudge was enough abuse for that day, and instead a different sort of guard visited her.
To this day I could still feel the cold in my bones as the Dementor leaned over her, its rancid breath in her nostrils as it opened its mouth to kiss her. Ginny welcomed this, as death was too good for her, but becoming a soulless zombie would mean she wouldn't feel her torture anymore. She had opened her mouth, willingly giving over her soul to the dementor. As it began to draw her soul from her body was when things changed.
The dementor let out a screech, struggling to get free of the connection between them to no avail. The pain Ginny felt was beyond the cruciatus, tearing her apart from the inside out. It was then that we made ourselves known the girl. We had slept within her since Harry Potter had killed the horcrux of Tom Riddle with a Basilisk fang. As the horcrux and Harry died we found refuge within her, using the last of our link in a desperate bid to survive. The soul energy from within the dementor gave us the power to awaken and assert control over Ginny, when we realized that there was not one, but three of us.
Lord Voldemort, the horcrux from Harry's scar, was actually the weakest of us. In our desperation, we had inadvertently dragged it along with us. I call it 'It' because Lord Voldemort was no longer human, he had become a Lich. We were completely open to each other at this moment, knowing everything about the others, and the other three were repulsed by Voldemort and all he had done to become what he was. The rest of us joined together, crushing what little will remained of it, and taking its knowledge for our own.
The strongest of us was Harry Potter. Harry got pulled along for the ride with the scar horcrux. All Harry wanted to do was save Ginny still; the fool not recognizing that she was beyond all helping at this point, as damaged as she was. Still, he was a whole and undamaged soul, the only one of us who could claim that wholly natural state. Harry was in control by way of default because of this, but being twelve still had no idea what to do.
This is where that third came in, Tom Marvolo Riddle. Tom was the diary horcrux who had brought about this unnatural, but precipitous merger. Being inside Ginny as she was abused affected Tom more than any of the others. Voldemort just didn't care, and wanted to heap the same abuses upon Ginny and her family as soon as he got his own body. Harry felt that this was the way the world worked, having suffered the same from his uncle while growing up. Tom had never felt so helpless in his life. Even the bullying at the orphanage had not prepared him for the level of abuse Ginny had suffered at the hands of the prison guards. Tom came to realize that what he went through as a child was insignificant compared to Ginny's suffering, and he wanted to protect her from this.
When Ginny realized that all we wanted was to save her, and that Harry didn't blame her for his death, she wept, and passed on what we needed to deal with being in a now female body. That left Harry and Tom, both of us feeding on the dementor in an attempt to assert our will on Ginny's body. Eventually we reached a compromise. We would allow ourselves to both die, using the energy of the dementor to combine the accumulated knowledge from all four of us and the life-force from Harry and Tom into a new person. This person would have two goals in life, the first being to fulfill that prophecy that we now knew half of. We both agreed that Voldemort was an abomination that needed to be ended at all costs. The second was to protect Ginny's now sleeping soul from further torment and find a way to give her back the childhood stripped from her unjustly.
I am this new person left behind. I am Ginny's guardian. I am Lord Voldemort's death. I am the child and heir of Tom Marvolo Riddle and Harry James Potter. I am Tamsyn Harrietta Peverell, and the wizarding world will rue the day I am released from my shackles.
Author's Notes: There will be those who immediately scream Mary Sue at me. I will endeavor to not do this, but Tamsyn will seem overpowered initially. She is not, but that is mostly because Voldemort in this story will be especially nasty. She will actually be weaker than him magically, but will be far more creative and intuitive. Her name is Peverell because Voldemort is aware of both his and the Potter's connection to the three brothers. Harry is dead, dead, dead. Tamsyn is the magical and spiritual child of Tom Riddle and Harry Potter born from their inaction with the dementor. She exists as a separate soul from Ginny, possessing her body while Ginny's soul sleeps.