Severus Snape's sleep was troubled by a strange dream. In fact, he had never had a stranger dream in his entire life, and never hoped to have one so strange ever again.
In his dream, he found himself in the body of a young woman. She sat at a vanity, humming some ancient Celtic or perhaps Elven melody as she brushed her waist-long hair. He couldn't see, as the woman's eyes were closed. But, he could sense that she was a witch, and a very powerful one at that. The woman opened her eyes, but looked not upon her mirror, but on a note written on parchment, one that Severus could tell that she had received several hours earlier. And in the instant he read the note, he knew he was somehow in the memories of Lily Evans Potter, nay, what had to be the last minutes of her life. The note read:
"The Devil has found a way to breach your castle walls. Take all that is precious to you and flee at once for your very lives."
The woman thought to herself as Severus was trapped within her form. "Severus, I'm touched. But, it would kill James to suspect Peter of what you accuse him of, and I know for a fact that the only way Voldemort could breach the Fidelus Charm would be if Peter went to Voldemort and told him willingly. I placed an extra charm on Peter that if he were tortured, he would die painlessly, a charm not even he is aware of. I know Peter's cowardice like the back of my hand! I don't want Peter to die at my hand, but if he meant what he told James and me, he would rather die than betray us. If he spoke in truth, we are safe. If not, we would already be doomed; Peter knows every place we could possibly hide were we to escape. Fidelis or no, we would be found.
"But, if Peter is a traitor, you have bought me the time to protect what is truly precious to me, Severus. I just hope it isn't…"
Severus and Lily were interrupted by a shout from below, James Potter with an emotion Severus thought he would never hear in the man's voice—terror. "Wormtail's betrayed us! Grab Harry and get out of here. Now!"
Lily stood and looked down into her son's cot. The child appeared to be sleeping. But, while he could sense that Lily hadn't noticed, Severus had. The child had been awake all this time, and was watching from his cot through one squinted green eye!
Lily looked at her son. Severus could feel the sadness in her heart as she said, "Forgive me, Harry. But, this is the only way. Know that I truly love you, and I always will."
She then took her wand and held it over the child, saying an ancient Kokirish incantation.
"My life for your life
My love for your love
My joys for your joys
My strength for your strength
My power for your power
My soul for your soul
All I have of worth
Is now all of yours
Plus what is yours of worth
Your death for my death
Your hatred for my hatred
Your sorrows for my sorrows
Your weakness for my weakness
Your powerlessness for my powerlessness
Your damnation for my damnation
All you have of scorn and derision
Is now all of mine
Plus all of mine.
All that is good I give to you
All that is bad I take to me
I suffer for you
You live now for me"
The Shield Charm of a Mother's Blood-love. "So that's how the Potter… Child… escaped slaughter" Severus thought to himself quickly. Seeing Lily Potter end her life for the love of her child was too much for the man who was an abused child; he could never speak ill of Harry again. And Severus knew, just as did Lily Potter, that even without Voldemort preparing to kill her, that she would not live out the hour; all her magic and almost all of her life-force was now successfully transferred into her son, who more amazingly yet was powerful enough to accept the entirety of this gift, rather than having it squandered into the ether. And, though Severus could tell that Lily was still unaware that her son was more than just waking up, Severus knew. The child not only saw, but he understood!
Moreover, he could sense something more horrifying yet. The fifteen-month old Harry Potter was preparing to magically return the gift! Severus knew that the child knew such a spell would be fatal, but he could sense that the child didn't care! Harry wanted to protect his mother, even at the cost of his own life. And Severus knew that the child would have succeeded, had they not been interrupted by the Dark Lord. But Severus knew something else the memory of the child did not. Had he succeeded, Lily Potter would be immortal, and even more powerful than the Magi of legend, even more powerful than Merlin himself!
But sadly, the memory moved at the speed of life, which didn't allow for a fifteen-month old prodigy to cast the most powerful, loving, and last spell of his life. The door to the room was savagely broken down to splinters by the Dark Lord.
"Give me the child, mudblood, and perhaps I might spare your life!" Voldemort exclaimed from the door.
"No" Lily answered. If you must kill, kill me! But spare Harry's life!"
"You are a fool, mudblood, like all your kind. Avada Kedavra!"
With the shouted curse, Lily Potter was no more. Severus now found himself in the blurry-sighted perspective of the fifteen-month old Harry Potter. The child looked up in silent horror at the evil man he knew had killed his mother.
"So, child, you are forecast by prophecy to be able to kill me? The Immortal Lord Voldemort?"
"...avada" the child thought.
"Now, it's time to see who's more powerful—The greatest Dark Lord ever, or a snivelling brat!"
"avada ke…" answered the child in his mind.
Harry raised his hand as Voldemort raised his wand. Severus watched in horror as Voldemort spoke and Harry Potter thought as one—"Avada Kedavra!"
Harry's curse, being wandlessly and silently cast, left his hand just after Voldemort's curse rebounded from Harry's forehead. And Harry's curse was far more powerful than any Severus had ever seen; not even the Dark Lord at his most powerful could have matched it. Both killing curses struck Voldemort full-on, vaporizing his evil body and driving his soul well out of the house. Severus also felt other things. He felt a muggle diary in Lucius Malfoy's home vault smoulder. He felt a locket in a hidden row-house in London singe. He felt an ancient signet ring hidden in a shack in the midlands almost warp. He felt Voldemort's pet snake Nagini writhe in excruciating pain, exceeding even the Cruciatus Curse. Yet, all these things, and others Severus couldn't identify held firm.
He felt Harry Potter cry. But the child didn't cry out of pain or fear. Harry cried in anguish for the loss of his parents… And in rage for failing to avenge them.
Snape awoke from the dream in a cold sweat, and became violently sick in his hovel. He was hiding now from both Voldemort and Potter. Voldemort, because his secret had been found out. Potter, because Severus honoured Dumbledore's instructions in the end, killing the old wizard before the potion Dumbledore made Potter feed him did the trick. Snape was forced to rethink his entire life because of that one dream. He came to two conclusions. First, if Voldemort could ever be killed, Harry Potter would indeed do it. Second, no matter how loyal he had been to the light, he was only living on borrowed time, awaiting the awakening of Harry Potter's inner child. Severus Snape was a dead man.