Due to chance, random variation, or perhaps fate, Lily and James Potter had twins. They named the twins Harry and Arnold.
On a fateful night in Late October, Lily and James were putting the twins to sleep. They were hiding in Godric's Hollow on Dumbledore's orders for reasons unknown. It must have been important, because Dumbledore insisted on the Fidelius - James also had to admit that the plan with the switched secret-keepers was brilliant. And yet he couldn't shake off the feeling that something terrible was about to happen. James tried to take his mind off the war, and a contented smile arose on his face as he watched his 1-year-old twins. The strange thing was that they looked so different - Arnold looked just like James (something James was very proud of), but Harry had much more delicate features, and had inherited Lily's green eyes. Something to do with magic? James wasn't sure and didn't really care. If he could get through the war without anybody close to him dying, he would be happy enough. Allowing his mind to stray to the twins again, he thought about the test results he had gotten from the mediwitch the other day. Apparently both Arnold and Harry were going to be strong wizards. All in all it had been a quiet, slightly stressful six months - which was about to change.
With a resounding crack, Lord Voldemort apparated into the Potter's front yard. Lily screamed.
"We have to get out of here. He's found us!"
James whirled around and made for the door.
"Peter, that fucking bastard. Take the twins and go!"
"James, I can't apparate! There's got to be some kind of anti-apparition ward on the grounds. I'll try to disable it!"
The front door suddenly shivered, and then was blasted open, throwing chunks of wood into the living room.
Lord Voldemort strode in, eyeing the defiant James Potter with an amused smirk.
"Potter, lay down your wand if you want to live."
Silently praying that Lily would find a way out of the house, James kept his wand trained on Voldemort's face.
"Hell no, you evil creature. What do you want from me?"
"I am a simple man, Potter. Give me your sons, and I will leave you unharmed."
"My sons are MY sons, you asshole."
Lord Voldemort sighed.
"Avada Kedavra."
Lord Voldemort strode over James Potter's body, following the faint trace of what had to be Lily Potter's magic. The trail ended at a locked door. He blasted it open.
Lily Potter fired the most powerful spell that she knew.
"Avante Cielocos!"
A bright white beam of light flew out of Lily's wand straight toward Voldemort, but the Dark Lord was just too skilled a duelist.
"Protego Maxima!"
A translucent black shield surrounded Voldemort, deflecting Lily's spell into the ground, where it fizzled and disappeared.
"I grow tired of these games, Lily Potter. Give me the twins, or die."
"Never!"
"So be it. Avada Kedavra!"
Harry Potter awoke to the destruction of his bedroom door, and silently and in terror saw his mother die. He watched as the snaked-eyed man raised his wand and sent a beam of sickly green light racing towards him. Then everything seemed to slow down, and as the green light came within a foot of Harry's face, the magic in the room erupted.
The blood ward that lay dormant in Harry's body flared to life, and for a moment the green light struggled to penetrate the barrier that had suddenly arose. Lily created the blood ward for this exact purpose - to protect her sons should she die at the hand of some evil wizard. As the green light and the barrier fought each other, it seemed for a second that this ultimate protection would hold. But in the end, the killing curse sliced through the blood ward and struck Harry right in the center of his forehead.
Once inside Harry, the curse made a beeline for Harry's magical core, seeking to sever Harry's soul from his magic and kill him as it had done to countless other wizards. But this time, something impeded its progress. Whereas usually the killing curse encountered no resistance from the core of the person it was about to kill, Harry's core, engorged from the blood ward magic as well as from his own fright, intercepted the curse just before it would have reached his soul. And then something happened that had not occurred for several millennia - the curse hit the core, and both shattered.
One-year-old Harry had no clue about the battle raging inside of him, but he did feel a blinding, sudden pain in his head, and before he lost consciousness he saw the most incredible thing: a wave of magic, in reality Harry's shattered core, spread out from Harry's body and flattened everything in the room. Lord Voldemort's body was utterly vaporized, the house was turned into dust, and Arnold Potter's body was scarred in several places from the magical energy. Arnold, who had just woken from the commotion, started crying when he noticed that his mother and brother were lying on the ground, motionless. And that was the scene that Severus Snape encountered as he stepped into the demolished bedroom.
When Severus Snape saw Lily's body, he broke. His Occlumency shields, strong enough to resist even Voldemort's mental intrusions, crumbled from the emotions that were swirling inside him. There was nothing, simply nothing, that he could do that would bring back the life of the one person who had ever cared about him. But ever the practical man, Snape realized that he could not stay long, as this place was about to become the center of attention for the wizarding world for many days to come. Before he left, though, Snape's previously ambiguous loyalties were resolved - he vowed to never again go back to Voldemort's clutches, and should the son-of-a-bitch somehow come back to life, he would fight with everything he had to destroy him once and for all.
Soon after Snape left Godric's Hollow, contingents from the Ministry and from Hogwarts arrived. Albus Dumbledore, Minvera McGonagall, Kingsley Shacklebolt, a whole division of aurors, as well as the Minister of Magic descended upon the Potter's destroyed house. Dumbledore was the first one to the scene, and he quickly performed some inspections, coming to several conclusions. He immediately realized that Voldemort wasn't dead, and filed away that information for later. But the next realization Dumbledore had, although seemingly obvious, was untrue. He decided that Arnold Potter, scarred as he was, must have been the one to have somehow deflected Voldemort's killing curse. Dumbledore also noticed something strange about Harry Potter - the boy had no magic in him! Had the Potters secretly given birth to a Squib, and hidden the information from him? Yes, Dumbledore thought; that was the only explanation - Arnold Potter miraculously blocked a supposedly unblockable curse, and Harry Potter was actually a Squib. He was brought out of his reverie by McGonagall.
"Albus, what should we do? You-know-who is dead, Lily and James are dead, and…"
"I propose that we split the twins up," said Albus.
"Arnold Potter has performed a feat of magic that deserves the highest Order of Merlin that exists. He is undoubtedly going to grow up to be an extremely powerful wizard, and thus I propose we send him to a wizarding family that will nurture him into the wizard he is destined to be. Any suggestions for what family young Arnold should go to?"
Molly Weasley's hand shot up.
"Albus, we would love to have the boy. We'd raise him as our own, and he would have several boys his own age to grow up with."
Minerva butted in.
"Albus, shouldn't we at least check the Potters' will?"
"Minerva, we both know that Lily and James would have wanted Sirius Black, and then the Longbottoms to take care of their children. As Sirius has just murdered over twenty Muggles and the Longbottom's have been incapacitated, I believe that the Weasleys are an excellent choice."
Another member of the Order of the Phoenix piped up.
"Also, if we don't decide this now, the Malfoys and the dark families will no doubt petition to host Arnold Potter as well. We must do this quickly, before they have time to react."
The Minister of Magic, anxious to have this entire situation over with and celebrate the end of the war, put a quick end to things.
"Then it is decided. Arnold Potter will go to the Weasleys. What about the other one?"
Albus's face became solemn.
"My friends, there is one more piece of sad news that I must share with you tonight. Harry Potter is a Squib. Not only is he a Squib, I do not sense any magic in him whatsoever. For all practical purposes, Harry is a Muggle."
Gasps arose from those present.
"We can't have a Squib growing up in our house, Albus, and I'm sure you can understand why."
"Yes, yes, Molly - I agree that Harry should go somewhere else. Into the Muggle World, perhaps? I know that Lily's Muggle sister would be willing to take Harry on."
"Yes, Dumbledore, I concur," said the Minister of Magic. "Squibs have no place in our world. Harry Potter will be brought to Lily Potter's sister, and he will live as a Muggle, without knowledge of the wizarding world. It is unfortunate, but sacrifices must be made for the greater good. Our business is done here. Let the Weasley's take Arnold Potter as their own, and someone bring Harry Potter to Lily's sister. Remember this day, everyone - the war is finally over. A toast to Arnold Potter, the Boy-Who-Lived!"
With that, everyone slowly dispersed, excited to tell their families and towns about how Voldemort had finally been defeated, and by a boy, no less. By the end of the week, Arnold Potter's name was known throughout wizarding Europe, and he had already begun his life with the Weasleys. Minerva took Harry Potter to the Dursleys, whispered a sad good-bye, and set Harry on course for his new Muggle life.