A few things:

I was thinking about where the first vampire came from and then this crazy idea popped into my mind that I thought could have plausibly explained it. If you like it I'll continue.

Pairing: Harry Potter/Tom Riddle (once Harry ages a few more years).

Which is slash – or guy on guy. Please don't make yourself look bad and begin to read only to suddenly find out it's something that you are "morally" against and feel the need to tell me that I am sick and going to hell.

Plot: Harry never wondered how vampires came into existence until he became a vampire hybrid after his battle with the Basilisk. His transformation into a unique blend of both wizard and vampire opens his eyes to the manipulations of Albus Dumbledore and he decides to fight back.

No sparkly vampires and will feature a darker Harry.

Here is a disclaimer that unfortunately states that I do not own anything that I am writing about and am merely hoping to play in another author's sandbox for a short time and what follows is for entertainment purposes only.

The pain was excruciating and nearly all consuming. It was worse than anything Harry had ever felt before, and that included his run-in with Professor Quirrell at the end of last year. Not even the piercing eruption that his scar had endured upon the physical contact with the disguised Lord Voldemort could compare to this.

The Basilisk's venom was something else altogether and Harry instantly felt like molten lava was flowing through his arm.

It had only been seconds since he had pierced the skull of the Basilisk with the sword of Godric Gryffindor, causing the great beast's heart to contract for a final time.

The beast then began to tilt backwards and Harry was partially lifted up until the fang broke off from the Basilisk's jaw and Harry stumbled around on his shaky legs. The thunderous crash of the heavy serpent sent the already unsteady and progressively weakening Harry tumbling to the ground.

What little else that Harry's mind could focus on as his face lay pressed against the cool ground was fixated on the giant, poisonous fang now lodged in his arm. The razor sharp and nearly foot-long object had gone in one side of Harry's arm and the tip was sticking out the other side. And the blood that began to gush out was the least of his worries as the pain began to consume him fully.

For several more seconds there were no sounds in the Chamber of Secrets. Tom Riddle was shocked at what he had just witnessed while Harry's vision began to blur.

A small part of him, the part not focused on how bad the pain was becoming, knew that he was dying; however, Harry didn't want to die with any part of the beast still in him.

Gathering the last of his strength and straining to stand as his legs began to succumb to the venom, Harry infused everything he had left in order to yank out the fang from his arm.

He tossed the soon-to-be cause of his death to the side as the last of his strength left his legs and he fell to his knees. If anything, pulling the fang out seemed to make the searing and otherworldly burning sensation pulse outwards from his wound at a greater intensity.

The Basilisk venom hadn't even been in his system for thirty seconds before his insides felt like they were on fire and he accepted that death was likely not far off.

In fact, Harry wished that the process would just go quicker because he couldn't bear the feeling that he was being burned alive.

As if his prayers were being answered his vision began to fail him and he could feel his awareness slipping away, lessoning the pain.

'At least I won't have to listen to the dark chuckle of Tom Riddle for much longer,' Harry thought to himself as he embraced death.

But then he felt a brush of cold air against his burning flesh and the faintest bit of colors, the last to reach his eyes registered as blurs of oranges and reds.

In the next instant Harry felt a sudden coolness in the very depths of where the gigantic Basilisk fang had pierced the flesh on his arm. Within seconds, that crisp and refreshing sensation continued to spread throughout his body and battled the fire that had to be raging inside of him based on how every inch of his body felt like it resting on hot coals.

'What's happening to me now?' he wondered as his vision began to clear and his mind became less foggy.

Focusing his eyes, the first thing he noticed was that Tom Riddle was glaring at him and the next was that Dumbledore's bird was standing beside his once injured arm.

"Fawkes!"

The Phoenix replied in a strange call and then took to the air.

Harry watched the Phoenix fly off into the shadows and disappear all the while vaguely remembering something about the healing property of its tears.

'Of course,' he realized internally as to what the cooling sensation rapidly spreading throughout his body must mean.

While Harry decided that perhaps maybe he wasn't going to die right this instant, his attention returned to Tom.

The handsome but deadly boy had a most displeased look upon his face, and Harry then noticed that Tom still held the holly wand that he had taken from him. Tom was twirling it through fingers while making sure that the end pointed at Harry every so often.

Harry knew that Tom was only thinking about the perfect torture.

For a moment Harry began to think about his limited options.

It wasn't like he could hope to fight back without a wand. His fearful eyes began to search for a way out, anything that he could use in a last-ditch attempt to survive.

He moved to grab for the sword still lodged within the Basilisk's head when he caught sight of the fang and the diary.

At this point Harry would try anything to be rid of the other boy and without hesitating went with his gut feeling that destroying the diary would destroy Tom.

Unfortunately, or rather thankfully as he would come to find out in the future, the pain returned just as his hand closed around the foot-long tooth.

A searing sensation, somehow worse than before nearly knocked the wind out of Harry. It seemed to emanate from his core and he could feel it slowly spreading outwards. Whatever this sensation was, it had to be at least ten times the suffering that he had so recently endured.

Harry was on his hands and knees and couldn't hold back the scream that erupted from his throat. In the next moment his limbs began to spasm as what felt like unholy lava shot through his veins.

Harry's face slammed into the ground as his body collapsed and his arms and legs gave out. Tom watched curiously as Harry began to flail from side to side as if he were being held under the Cruciatus Curse.

Surely Tom had been meaning to subject the Boy Who Lived to something similar but even that curse didn't elicit this much pain.

For one of the first times in his life Tom was at a loss for what he was witnessing. Hadn't the Phoenix's tears cured the boy from the Basilisk venom?

But what Harry was suffering from was so much more than the Basilisk venom, and it was all because it had been mixed with the tears of a Phoenix. Because what even Fawkes didn't, no, couldn't know was the effect of mixing two such powerfully potent substances that were equally balanced.

True, Phoenix tears could heal just about anything, except they couldn't cure this. However, that didn't mean that Fawkes' gift hadn't saved Harry's life.

The strength and magic of the tears had fused with the very essence of the venom to produce a delicate and eternal balance of healing and destruction.

The unholy union that was beginning to ravage every cell within Harry's body both perfected and killed everything that it came into contact with, leaving behind something that was simultaneously alive and dead. The one thing that prevented it from leaving Harry's body permanently unchanged was his magic. A not insignificant part of his magical ability would forever be lost to ensure that his body grew until he reached adulthood and came to control the full extent of his magic – and when that happened it would take even more of his magic to allow him to keep his warm blood and beating heart, forever remaining in the prime of his life.

But Harry didn't know that any of this was happening or would happen while he lay on the dank floor in the Chamber of Secrets, his body twitching uncontrollably.

Harry also didn't know that this new and potent substance had begun to affect the soul of Lord Voldemort that resided in his scar. Only, the piece of Lord Voldemort's inadvertent Horcrux didn't have enough magic to fight off the venom as Harry's magic had.

The mistaken Horcrux was defenseless as the combination of venom and Phoenix tears washed over it and permanently fused it to Harry for all time.

It was at this same moment when Tom Riddle now had an immortal Horcrux that something unexpected happened.

The same venom that was currently ravaging Harry's body and had also bound the inadvertent Horcrux to Harry had also found a way to affect the remaining pieces of Voldemort's soul through whatever magic connected Horcruxes to both each other and to the original soul. Simply put: it healed them in a similar but distinct manner to its effects on Harry's body.

This time the Basilisk venom and Phoenix tears ensured that Tom's soul was first healed and then made to never split ever again.

Only, since the young Tom Riddle standing within the Chamber of Secrets possessed the largest fraction of the original Voldemort's soul since creating a Horcrux splits it in half each time, every other piece of Voldemort's soul – including the part that resided in the incorporeal form floating through a forest in Albania – was forced into the more whole and stronger vessel of Tom Riddle that stood only a few feet from Harry.

The change hit Tom just as quickly as it had hit Harry, so much so that he dropped Harry's wand as the memories and experiences of all the other pieces of his future self flew back into his body. As each bit of soul reconnected the venom worked to bind them so that they could never be separated ever again.

He could feel each unwanted addition and his mind struggled to resolve all of the strange scenes that flashed through his eyes. It was almost too much for Tom to take and he began to stumble towards the exit; his only thought was in getting away from Harry Potter as fast as he could in the hopes that whatever was happening to him would stop.

The only person to immediately benefit from the combination of Basilisk venom and Phoenix tears was Ginny Weasley. The young first year who had been moments away from death was no longer having her energy being siphoned off from a Horcrux. As each soul had rejoined with the one inside of Tom Riddle his physical presence was strengthened and the venom had then severed Tom's connection to the girl.

Still, it would take her several hours to recover from the amount of energy that she had lost, and then several more until both her and Harry were rescued.

However, by that time Tom Riddle would be unable to make another Horcrux and Harry would be a vampire-wizard hybrid that was essentially immortal. Of course, it would take each some time to discover just what the hell had happened to them, and longer still to realize that they would be forever tied to one another.

For Harry would be an immortal hybrid who housed the one surviving, but permanent, Horcrux of Tom Riddle.

And in time they would come to discover just how important that connection was as neither could truly live without the other.

Thoughts? I have a really solid idea for this in mind and was the reason for the posting. Hopefully I will have made you believe that what I have done is plausible – or at least you are willing to turn a blind eye to it – in the hopes that you give these two a chance.