Spoilers: Pretty much all six books are fair game but this is AU so nothing too specific.

Disclaimer: Harry and co. belong to JKR. I own nothing, literally. Unfortunately.

Summary: Sybil Trelawney had made just one true prophecy before her death at the hands of Lord Voldemort, never knowing the words she didn't even remember would shatter the world. As the Dark Lord acts prematurely, forcing a traitor to become a hero and driving the frantic parents to make a heart-breaking decision, the fate of Harry Potter is changed forever. AU

The Strength of Necessity

Prologue – Foreseen and Unforeseen

The one with the power to vanquish the Dark Lord approaches...

born to those who have thrice defied him,

born as the seventh month dies...

and the Dark Lord will mark him as his equal,

but he will have power the Dark Lord knows not...

and either must die at the hand of the other

for neither can live while the other survives...

The man maintained an eerie stillness, frozen with fear, even as his companion fell to the floor writhing in pain. His eyes remained pasted shut even as the screams grew to intolerable levels. A voice, quiet, but powerful and laced with venom, cut through his terror. The screams abated and his companion fell beside him, dead. The man opened his eyes.

"My Lord." He bowed with as much grace as he could muster under the circumstances.

"Failure, as you can see, displeases me."

The words contained no direct threat but he understood the warning. Marcus dared a gaze to the fallen man who had displeased their lord. He would not fail.

"What have you found?"

"The prophecy, I believe, could relate to one of two families. The Potters and the Longbottoms have fought against you thrice and somehow managed to survive. Both have got an infant son that was born near the end of July last year."

The Dark Lord raised an eyebrow, "Is that all?"

"I believe that the Longbottom boy is the more obvious choice. They are purebloods and Potter's wife is a mudblood, after all. The prophecy mentions the boy being marked by you; I think it may refer to a wound. You literally marking him somehow. My Lord."

"I trust that a matter of such importance earned your utmost … discretion?"

"I spoke of this to no one and the seer is no more. No one else knows of the prophecy but you and I now, Master."

The Dark Lord seemed to consider his words and a small smile graced the Master's lips.

"Very well, Marcus. You have done quite well and you will be rewarded for your effort."

Marcus bowed once more and mentally sighed in relief. To anger the Dark Lord was tantamount to suicide, but to please him meant power, fortune – everything he had dreamed of when he first received the Dark Mark. It was pure luck that he happened upon Sybil Trelawney that July night almost a year ago. And it was magnificent fortune that he was the sole audience to her prophecy in the dusty silence of the Hog's Head when a lazy evening downtown turned out to be the greatest opportunity of his life. He began a conversation with her more out of boredom than any actual desire to converse with the woman. He immediately regretted his decision when she launched into a tirade about inadequate Headmasters that have no respect for the sacred art of Divination or those blessed with the Sight. He learned that Dumbledore had rejected Trelawney's application to teach at Hogwarts. Marcus was about to leave when she fell into a trance and recited the words that changed his life. Armed with the prophecy, he became one of the Dark Lord's most valuable servants. If the prophecy had fallen into the wrong hands… he shuddered at the possibilities.

As Marcus bowed to kiss his Master's robes before the Dark Lord, Voldemort raised his wand and uttered a single curse. Marcus Wayfeather died, still dreaming of the rewards his Master had promised him.

Lucius Malfoy enjoyed his position in the Dark Lord's Inner Circle most of the time; it afforded him more influence than even his family's large fortune, and he found he enjoyed the power. Still, there were moments, like now, when he seriously doubted his allegiance. Lord Voldemort had ordered him, along with his lunatic sister-in-law Bellatrix, to 'pay a visit' to the Longbottoms. While he never quite developed the taste for cruelty that the other Death Eaters cultivated, it never really bothered him either. But, generally speaking, he liked knowing why he was mercilessly torturing someone. It made the taunts that much more effective. With a little wheedling he could usually get a reason from the Dark Lord but today his instructions were startlingly blunt. They were to kill the entire family, including the child. Lucius was curious, but self-preservation overrides curiosity any day so he wisely kept his mouth shut and left to meet Bellatrix.

Wayfeather was a fool, a useful one, but a fool nonetheless. He had, albeit accidentally, discovered the prophecy over a year ago and managed to decipher it. If the Longbottom boy was indeed his destroyer, it stood to reason that a certain distance would have to be maintained. In his rather dramatic rise from Tom Riddle to the most feared wizard in the contemporary wizarding world he had, admittedly, made some mistakes. But careless stupidity was never among them. This was the reason he considered just who to send to carry out this particular task with great care. Bellatrix was a given, she would neither question nor fail the mission. But she did have a tendency to go overboard. He needed someone else with her to keep her on task. Snape was more than capable, but Dumbledore had been too much of an influence on him of late. He quickly ran through his options and arrived upon Malfoy. He would have enjoyed watching the death of his prophesied destroyer but prudence dictated otherwise. Disappointed at not being present, he sent Bellatrix and Malfoy along with a small contingent of Death Eaters to kill his potential murderer.

He now considered the other boy. Harry Potter. Pettigrew was the obvious choice, but that coward would most likely balk at having to kill the brat by-product of his friends. Or, worse, he could grow a conscience and scurry back to the headmaster. Not that he knew any information of worth, but still, the traitor was beginning to be more troublesome than useful. He could commission another of his followers to kill the boy but that would raise more questions among the Death Eaters and Voldemort knew that information was a commodity almost as valuable as power. None of his followers would know the reason the two families were targeted. No, he would have to kill the Potter boy himself. Moreover, the murder of a soul so pure as a child's was powerful. Engaging in such destruction was a potent magic indeed.

"Ma-master." Peter fell to his knees. He hadn't expected this. In the year since he had received the Dark Mark, he had seen the Dark Lord twice and hoped fervently never to have that particular pleasure again. The man, or what remained of his humanity in any case, was terrifying. Gaunt features and skin pulled tightly over the delicate bone structure of his face belied a bloodcurdling presence. And his eyes, they could only be described as serpentine. And Peter hated snakes.

The usual telltale twinge before the mark erupted in pain had been his only warning before the Dark Lord stood in front of him.

"Pettigrew." It was both an acknowledgement and a threat.

"Yes Master."

"Where is your charge, Wormtail?"

Peter froze. What did he want with Harry? "Harry, my Lord?"

His question was met with silence. "Upstairs. Harry's upstairs."

He followed as the Dark Lord ascended the stairs. Peter could understand him going after the Potters; they had been fighting for years – but Harry?

Lord Voldemort stood peering, almost fondly, into Harry's crib and Peter fought the urge to bundle the child into his arms and run. He had betrayed his friends, true, but that was necessary. The Order wouldn't win this war, not with someone like Voldemort as the enemy. Voldemort was capable of anything and that determination would win him the war eventually. Peter didn't believe in miracles anymore. He never wanted to hurt his friends; he simply didn't wish to die. Was that so wrong? He was twenty-four years old and he wanted to live.

"Such a young child. So powerless and yet…"

Harry? He was barely a year old. He had yet to master walking. What did the most powerful wizard alive want with him?

"Potential problems, Pettigrew, must be dealt with in a timely manner."

"Oh Merlin." He had said it out loud. The mad man was going to kill Harry. The child whose birth he had anxiously awaited. The child he loved to spoil. The baby who always had a toothy grin in store for him. Harry, who never minded that his wand work lacked finesse as long as he made colorful bubbles for the child to pop playfully. He had been so jealous when Sirius was named his godfather; Wormtail loved Harry as much as Padfoot. Harry was the first of the next generation and a true innocent.

The Dark Lord raised his wand and aimed it at the still sleeping child.

He was babysitting today. James and Lily had work for the Order and he was frustrated at being left behind yet again.

The hooded man tilted his head as if momentarily considering which spell would be the best.

But he had fun; it was impossible to be ill tempered around Harry.

The words spilled out slowly. "Avada…"

"NO!" He wasn't aware of his screaming nor knew exactly what his body was doing. A single thought pervaded his entire being: save Harry. Without really thinking things through, in a true Marauder fashion, Peter Pettigrew proved the Sorting Hat's placement of him in Gryffindor apt by rushing ahead and taking the full brunt of the Killing Curse.

Bellatrix loved screaming. There was something raw, basic, about screaming. It was scintillating.

Frank and Alice Longbottom had put up quite a fight and that made this session that much more enjoyable. The others had left at her orders after the Aurors were subdued. Only she and Malfoy remained and Bella decided to brush up on her spell work. She always preferred the simplicity of the Cruciatus. It was direct and simple yet oh so effective. Malfoy, she knew, enjoyed the slow-acting curses. The kind that festered in the body for hours before showing any actual effect. Where, she wondered, was the fun in that? She liked her victims to suffer now and she especially liked to watch.

Malfoy was getting restless and the couple was no longer as much fun. She was ready to complete the mission and kill the family. Unexpectedly, the Dark Mark was activated. It wasn't the usual slow burn but rather an odd suction. Almost as if the Mark was trying to retreat into her skin. Something was wrong.

Malfoy sensed something as well and stood questioning her. The Mark burned again, radiating an urgency like never before. The Dark Lord was calling for her.

"We've got to go to him. Now!"

Malfoy faltered for a moment. He quickly cast the Killing Curse on the Longbottoms before turning back toward Bellatrix. "The chil…"

Bella could feel the pain, the need; they had to get to the Master.

"NOW!"

Her anxiety spurred him into action. They apparated to Lord Voldemort, leaving behind the corpses of the couple and an oblivious young child hidden under an Invisibility Cloak and still under a silencing charm hastily placed by his mother seconds before the attack.

They allowed the pull of the Dark Mark to lead them to a house and found the Dark Lord hunched, struggling down the stairs. They watched, horrified, as he lost his balance and fell. Bellatrix rushed to his side.

"Leave now, Malfoy!"

She had never seen him like this; Master was always in control. Never desperate. Never… in pain?

Malfoy eyed them in rapt fascination before he left.

"Weak, Bella. So weak."

Her heart broke.

"Away...somewhere safe. They cannot see…"

She understood the implication. Master had offered her a vision of a glorious future for wizardkind. He had given her a mission, a purpose. She would protect him, both from the power hungry Death Eaters and from the others. Bellatrix Lestrange was a true believer.

The argument raged on for days. Oddly reminiscent of their school days, he and Lily somehow wound up on the opposite sides no matter what side he took. The yells of the earlier battles, silenced by charms to keep Harry blissfully asleep, gave way to a capricious peace. The decision had been made; it was now simply a matter of going through with it.

"Why Petunia? Why can't we go…somewhere, anywhere, and take Harry with us?

James slid onto the sofa next to his wife. "There is nowhere Voldemort won't find us, Lily."

"We could leave the wizarding world. I know it would be hard for you but…but we could live like Muggles. Harry would be safe and with us."

For a moment, he was tempted to agree. They could leave now, their small family safe and intact. But that was a lie. They would never be safe until Voldemort was gone.

"We have to do this for Harry."

"He'll be safe?"

Her face was encased in dried tears, her hair haphazardly pulled back; James had never seen Lily like this before that Halloween.

The Dark Mark greeted them upon their arrival home on Halloween. They rushed into the nursery to find Peter dead, with his Dark Mark burning a livid crimson, and Harry in restless slumber. The following week had been spent in a flurry of research and activity. When had Peter turned? How much of the Order was compromised? Why were they attacked?

The simultaneous attack on the Longbottoms only added to the confusion. The loyalties of even the closest of friends had been questioned, scrutinized and reevaluated. The Potters and Neville Longbottom took up temporary residence at Hogwarts. After an examination, Dumbledore revealed that Voldemort himself had killed Peter and the odd scar on Harry's forehead was most likely a result of an aborted Killing Curse. The latter was only conjecture. And several questions remained, the most important of which being: why was Harry spared? Was Voldemort's attack an afterthought to killing Peter, abandoned when some other, more important matter arose? For that matter, what exactly had Peter done to merit death at the hands of Voldemort and not just a random Death Eater?

The Potters were always a target for the Death Eaters and their position within the Order ensured that they would remain so. When Harry was born, they were cautious but hopeful that he could be protected. Now, James feared for the safety of his son. As long as the Potters kept fighting, they were targets. But to stop fighting was not an option. Voldemort had to be stopped at any cost. So the fact remained that, as long as he was with his parents, Harry was in danger.

"Tell me we're doing the right thing."

The response was automatic. "We are, Lils, we are."

Neither he nor Lily was able to write the letter. He began several, but the act seemed somehow … final. Dumbledore provided them with the final draft. It was concise, yet informative. Because of Lily and James' untimely demise, care of Harry had been transferred to Petunia.

It was heartbreaking but it was necessary. With the Fidelius Charm in place, Harry would be far safer in the Muggle world with the Dursleys than he would with them.

At Privet Drive, Lily finished the charm, and James was unable to move his gaze from the house. His only child was now in the hands of Muggles that despised magic, and would think himself an orphan. He would, no doubt, have no knowledge of or contact with the wizarding world until his eleventh birthday. Or until Voldemort was no longer a threat, whichever came first. James was hell-bent on ensuring that the latter occurred as soon as possible.