Disclaimer: Only the plot and a couple of the spells used belong to me, the rest belong to JK Rowling.
A/N: This is just a story, not a theory like Harry's Heritage was (except for the part about Fudge).
A coal black raven swooped down from the gray sky and alighted itself silently on the gnarled branch of a tree twisted by age. Below it stood two figures, the raven peered at them and cocked its head so it could hear more clearly. One of the men was very tall with pasty white skin, spidery fingers and blood red eyes; the other was also pale with platinum hair. The bird could see the fear emanating from the blond like sweat.
They spoke in hushed tones and it was clear that the snake-like one was giving instructions. The raven hopped down lower to make sure he heard every word. Dumbeldore himself had told him to make sure he heard every conversation and see if it had clues that should be recorded. The red-eyed man was known to the world as Lord Voldemort and the bird knew that the man he was talking to was Lucius Malfoy.
"... And what of our spy at Hogwarts?" Voldemort hissed angrily.
"He was caught, my Lord, just after Harry Potter escaped with the dead boy's body," he said in a submissive tone.
"Fool!" Voldemort gestured with his wand and an electric shock seemed to course through Malfoy's body leaving him gasping in pain, "I know that Crouch was caught but how? And what did he give away?" he sent another jolt through Lucius to prompt him.
"My Lord, he was caught while attempting to kill Potter," Lucius paused, then seeing the look on Voldemort's face continued on hurriedly, "However, Fudge heard of your return and sent a Dementor on him before he give anything away. Right now he is slowing down Dumbeldore and McGonagall by pretending to deny your return," Lucius finished his report.
Voldemort opened his slit of a mouth again to reply but glanced up sharply, a cruel smile coming to his lips.
The raven realized that he had been discovered and beat its wings frantically to get away. But the harder it stroked its wings the less distance it covered until it realized it was being pulled backwards into the waiting hand of Lord Voldemort.
"Well Lucius, its seems we have caught our spy red-handed," Voldemort chuckled evilly.
"My Lord, this is no Animagus, who is it?" Malfoy inquired.
Voldemort, however, was ignoring him, "My dear Severus Snape, what are you doing here? The gathering ended hours ago and you all left in different directions," The Dark Lord said mockingly. Snape cringed (no mean feat for a bird).
"It seems Mr. Malfoy does not believe it is you, or does he? I have known you were the spy since you came back, Severus, so it matters not what you have told Dumbeldore. Those plans were changed the minute I felt your presence dissaparate. Well, throw off your feathers and show your face! Unless you are unable too..." Voldemort paused dramatically again, "Unless this is a potion of your own devising."
At that moment Snape felt like he had swallowed one of his own poisons. All the plans he had told Dumbeldore...changed. But at that moment he felt tendrils of a Mind-Seeking spell reaching and taking out images of the potion he had created.
"Ah, I see, you and McGonagall created it and it won't wear off for awhile, will it? Well, I defy such a simple potion: extransformarus!"
Snape threw back his head and began a caw that steadily grew into a scream as he was changed unnaturally inch-by-inch from bird to human. He was left gasping for breath, lying on the grass while the Dark Mark burned like acid into his skin.
Taking no chances, Voldemort nodded to Lucius who immediately muttered a word that sent black cords flying out of his wand to envelop Snape, gagging him as well as binding his limbs. Now Snape could only stare up at Voldemort, not bothering to hide the terror in his eyes. The jig was up and the Dark Lord was not one to be fooled by any excuse.
"So it is you, Severus," he said in a tone that showed he had never believed otherwise. "To think you were smart enough to brew such an amazing potion but not smart enough to mask your thoughts while you were at it. Not that it would have fooled me.... I could kill you right now, Severus, but if I meant to kill you, you would already be dead and rest assured it would have been excruciatingly painful. I will probably kill you eventually but right now all the trust that Dumbeldore has invested in you is far too useful.
Snape, who had begun to squirm in effort to break free of the bindings froze as he heard this. He wouldn't be killed right away is what Voldemort was saying. He knew that the Dark lord could use him as a puppet: wiping his mind as clean as any Dementor could and inserting his won will into his body. Or with Snape at his disposal he could, using polyjuice, send one of his more loyal followers into Hogwarts in his place. No one would know as long as the real Snape didn't show up, which he wouldn't. But Voldemort was talking again and he focused to hear what he was saying in his snaky whisper.
"...But I already have enough spies in the wizarding world at the moment and even in Hogwarts. Young Draco Malfoy is living up to his father's example, bring new of Harry Potter to me monthly. Even the Minister himself is leaning towards our side. You shall be an example to other as to what the punishment is for betraying the Dark Lord!" with that Voldemort raised his wand and cried the Cruciatus Curse, holding it there until Snape had one unconscious with the pain. He gestured again to Lucius who transported himself and Snape's prone body back to their lair, before Voldemort apparated himself
When Snape finally awoke he was hanging by his wrists a few inches off the ground in a dank, run-down cellar. He lifted his slowly and gave a muffled scream as a bolt of pain shot up through his back. His reaction was to curl up but that sent even more intense waves of pan through him, causing him to scream louder and finally black-out.
The next time he awoke it was to the Cruciatus Curse. He whimpered and wriggled on his chains, which only made it worst. During a pause he opened his eyes to see Avery, Malfoy, and Pettigrew in a semi-circle around him, with cruel expressions on their faces. So Pettigrew was alive, Snape realized, and all along he thought Potter had been raving....
The smile widened on Pettigrew's face as he cried, "Crucio!," sending Snape in convulsions. This time though, Snape bit back his screams and when the bout was over he gave his most contemptuous sneer at Pettigrew. Of he had his wand he could take the man out without even breathing hard, and Peter probably knew that. That's probably why he enjoyed torturing so much. Due to his lack of anything resembling talent he needed people to be in the same state as Severus to have any power over them. Snape hung on for another five minutes before spiraling back into welcomed unconsciousness.
Snape knew not whether days, weeks or months had passed. Everything had become a blur. He was either being tortured but Voldemort and the Death Eaters or unconscious. The only reason he wasn't dead was because of a vile potion they continually poured into his mouth. The potion itself healed his wounds and kept him from starving or dieing of thirst or exhaustion. The irony of it was that he himself had created it while in service to Voldemort. It was being used as it had been planned to be: keeping torture victims alive and coherent until they had all the information they needed out of him.
But Voldemort wasn't interested in information from him yet, so there was no relief in giving false information and being killed once his usefulness was done. The Dark Lord biding his time, waiting for the right moment where he could re-insert Snape (or his appearance) back into the mainstream of Hogwarts.
Back to the present, Snape was passed the point where he felt individual pain. It had all merged into one long nightmarish agony. Hanging by his wrists, cringing at the slightest sound which might mean another torture session.
He almost yelped as he heard a sounds descending the steps to where he was hanging on the wall. So they were coming back for more he sneered to himself. But there as something different this sound. It was lighter then the other, almost like the feet were padded, and there was the distinct click of animal toenails on the stone floor. When he finally gathered enough strength to look he found himself face-to-face with a bear-like black dog.
The Grim. Snape felt an odd sense of relief wash over him like balm for his wounds. The Grim meant Death which meant no more pain, no more torture, no more fear of betraying Dumbeldore. He lowered his head again.
Now all he could see was its black feet, but something was wrong.... They were changing, elongating, and losing they're form. He looked up again just in time to see the black fur recede until it was only the tangled mane of Sirius Black.
Snape almost cried. First Voldemort, then the Death Eaters, and now black had come to beat him while he was down. Was he here to add his own little session of torture on top of all the others? Just because of all the times they had fought as children?
Snape began an enraged growl way back in his throat, but it halted before it came out into the open. He realized, stunned, that he didn't hate the man! The face that had so often sent him into a killing rage now held no power over him! And he knew why. After all the pain, shock, hatred, and fear; his childish dislike of Sirius dwindled to less then nothing. Did it matter that the man had played a trick on him that almost got him killed? Not really, he hadn't killed him, and it had been so long ago.... Severus went limp. Why bother fighting? Just let him do what he wants.
"Well, Snake, you look a little worst for wear," Sirius chuckled slightly, but it was very strained. Though Sirius was not having the same revelation as Snape, he was too horrified by Snape's beaten form to jest about him.
He cleared his throat an continued quietly, "Dumbeldore sent me out to find you. We didn't send anyone sooner because we didn't know where to look and we couldn't spare anyone either. But Harry heard some Slytherins (Death Eater's kids) talking about where you were. I was sent as soon as we confirmed it," he took a deep breath, coughing because of the musty air, before pulling a small glass vial with a green liquid in it out of his robes. Snape looked at him inquiringly, he didn't trust his voice yet. He was afraid that if he spoke it would turn out to be a dream and he would wake again to being a source of amusement for the twisted Death Eaters.
It's the same potion you used to turn into a raven. Without it..." Snape herd these words and recoiled. How many times had Voldemort turned him painfully back and forth between raven and man? Sirius grabbed his chin and forced him to look into his eyes, a motion that sent jolts of pain through his spine, but he would not admit to it.
"I can't get a man out of here unnoticed so you will have to be a bird. I don't know yet what you've gone through but this won't hurt!... I promise," Sirius finished. Snape finally nodded and Black tipped the bottle into his mouth.
The transformation was done in moments, but Sirius waited a minute before becoming a dog again. It was a good thing he did for as Snape's arms shrank and became raven wings, he slipped out of the manacles and almost fell to the floor before Sirius caught him. He put the bird down as gently as he could but even then it gave a small squawk of pain. Sirius changed form, picked up the broken bird's body and trotted ff into the night.
A/N: Well, that parts over. Don't worry, the next chapter is coming momentarily I just thought it would be more dramatic if you needed to click the button to fnd out the rest :).