A/N: This is an idea I had while I was lying in bed one night, and it still sounded quite good when I woke up, so I supposed perhaps I should write it.

Summary: Severus is taken over by a force greater than him, a force that makes him do terrible things …

Disclaimers: I don't own any of the characters – they belong to JK Rowling. But the idea is mine.


Chapter One

Severus Snape, Potions Master at Hogwarts, stared steadily into the liquid-mirror over his desk, and swallowed. Slowly he raised his hands to his face and traced his fingers over the pale skin, over the hooked nose, rubbing, massaging. He caught his own eye in the glassy surface and studied himself, keeping his face carefully expressionless. He swallowed again. Now was the time. He let his hands travel down his body, across his bare chest, caressing his stomach. When he reached the top of his trousers, he stopped, and he let the delicate flesh quiver for a second.

'Do it, Severus.' The black rock on Severus' desk flickered.

Severus moved his head sharply up, back to the mirror, watching the dark eyes that stared at him blazing. Then he closed his eyes and plunged his hand under the black material.

The stone flared, and then went completely black.


When Severus woke up a few minutes later to find his body spent, he remembered nothing.

He knew what had happened. It had happened before, many times. He had grown accustomed to it, and now he only felt a slight twinge of helplessness.

He threw a slightly furtive glance around the room, and his gaze came to rest on the obsidian in front of him. It was still at the moment, lifeless on the polished wood. Most people would probably be fooled. But Severus was not most people, and so he kept watching, waiting. He was not wrong.

The Mark on his arm exploded into pain, and the obsidian suddenly burned, gleamed blood-red, and Severus' gaze was locked through his agony, and a voice whispered, a voice that spoke in a harsh, spitting language, reminding him of the thrill of the hunt, the joy of the kill, the exhilaration he always felt seizing a living body and beating it, squeezing the tenuous life from it until it was nothing but a corpse, a tribute to his prowess, and in all this excitement stood the clear image of a boy, sixteen, smooth skin unblemished and clear, with bright emerald eyes, and those glasses, those stupid fucking glasses …

Severus only thought to throw his robe around him before he seized his wand and let the whisper envelope him again, let it take him out of his rooms and towards the boy, the bastard child he hated, for the first time, to eliminate him.

The obsidian lay, still glowing, in his room.


Harry Potter, meanwhile, was tiptoeing through the darkened common room, Invisibility Cloak tightly kept to his shoulders. His fingertips tingled, and there was a pleasant warm sensation between his legs. He smiled in affectionate anticipation. Draco would be waiting. He glanced down at the Marauder's Map, more as a nervous twitch than as a suspicion that anyone was coming. All seemed normal.

The memory of the beginning of Draco's and his relationship crept into his mind. That had been anything but normal.

A scuffle, a few blows exchanged without any real desire to inflict pain, rolling madly on the floor, trying to pin the other down to gain the freedom he needed to yell insults at his enemy … and then the sudden tightening at Harry's groin, the startled expression on Draco's face. A moment of stillness, calculating and consideration, and then Draco's arms wrapped around Harry's neck and they were kissing, and Harry had never known such desire, such surprise so expertly moulded into pleasure …

Harry's stomach jolted as he remembered that kiss, the utter dismissal of anyone else in the world just so they could be together. Draco hadn't visibly changed since then – he and Harry still insulted each other in public, but now they did not touch, for the certainty that they would instantly collapse into each other's arms. Even the words were said more casually, and they were interspersed with silent kisses that had to be substantiated at night. Draco had been promoted from deliberate exclusion from Harry's life to desperate inclusion in it. All they had left to do now was to hope that nobody noticed.

A sudden movement on the parchment in his hand suddenly made Harry look down, and stiffen, and gasp inaudibly. Snape was no longer in his rooms. Now he was moving fast, running, it seemed, and he was heading straight for Harry!

Harry knew he was invisible, of course, but it didn't stop him being more than a little nervous – Professor Snape wanted him expelled … he could still remember the incident in the Shrieking Shack. Snape's eyes – they'd been so bright, burning almost …

Harry shuddered. He had to move.

He turned and started to jog back in the opposite direction. Then he heard quick, heavy footsteps, and began to sprint in terror, intent on nothing but getting out of Snape's way …


Severus could not control the urge that was taking him towards Harry, could not stop even though an irritatingly calm voice told him that the whole thing was an illusion, that he would regret killing the boy …

He was laughing as he ran, bloodthirsty snarling laughter, and his wand flashed red fire. The kill was close.

Then the corridor veered, and there was Potter, clinging to a useless cloak, face aghast that Severus could see him. God, he was so stupid, of course Severus could see him, the Cloak didn't work when he was looking through the eyes of his Master, and everything looked red.

Severus ripped the cloak from the boy triumphantly and struck him on the side of the head, sending him flying to the ground. The bloodlust roared in his ears, and he advanced on the cowering Potter, ready to carve his Master's designs into that beautiful pale skin, to make him cry out in agony. 'Potter …'

In Severus' rooms, Dumbledore, roused in the night and waiting for him to return, idly picked up the obsidian and looked into its surface.

Then everything was so greeny-blue and the red was gone, and Harry was Harry, and Severus gave a low moan, although he could not remember it, as he realised what he must have been about to do. 'Harry, I'm so sorry, please, it's me, please, I'm not going to hurt you … Harry, please, I can explain.'

Harry stared at him in mingled suspicion and horror. 'What are you doing?'

'Harry, I'm so sorry, I … I lost control for a few minutes. I'm myself again now. Please, I don't want to hurt you. The stone … in my room …' He gasped. Someone must be there. The stone only went quiet if someone saw its heat – someone must be in his rooms. He looked again at Harry, pleading that he would believe him so that he could leave.

Those beautiful arms were entwined around his neck, the bewildered lips on his own, and he understood suddenly the undertakings his Master had forced on him, for he wanted the boy so much …

'NO!' Severus forced the cry out, and the image fled. It had never happened, surely … he couldn't have done that. 'Harry?'

'Professor?' Harry replied with a totally bewildered expression on his face. Had he seen the desire in Severus' eyes? No, of course he couldn't … he was much too frightened to register anything that subtle at the moment.

'Harry, listen. I have a stone in my room, black, obsidian …'

Dumbledore decided that Severus was not returning anytime soon, and left Snape's rooms. The obsidian began to glow slyly.

Suddenly the boy he was talking to was an object of intense irritation, a Gryffindor who must be crushed if his Master was to rule, and Severus lunged forward and grabbed the boy by the shoulders, and shook him and struck him, and fumbled frenziedly in his robes for a knife, a weapon of some kind, so he could bleed the life from this man-child. His fingers closed on something cold, something hard and metallic, but it was not a weapon. Instead he yanked out a piece of shiny hematite, pure grey and so bright, so powerful. His eyes were lost in its surface.

'Neutral,' he said distractedly. Holding the stone seemed to oppress the bloodlust in his heart, and dissolve it in calm. He looked back up at Harry, who was shaking violently. Severus could tell that every inch of his body wanted to tear from his grip and flee. Then he remembered what he had done – he had tried to kill him. He had tried to kill the hero of the wizarding world. The enormity of killing the Boy Who Lived suddenly hit him, and he felt his face grow very cold. 'Harry -' he faltered. The name held a peculiar significance in his stomach, and it churned. Something flickered between his legs.

Then, all at once, he broke down in tears, and fled into the darkness.


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