Chapter Text
Our story begins soon after Severus Snape witnesses the prophecy given by Sybil Trelawney and tells the Dark Lord whilst also begging for his one loves life, Lily Evans. Unbelieving of the Dark Lord’s words to spare her, he presents himself to Albus Dumbledore, once his Headmaster, now his leader. Albus promises to protect Lily, and in extension, her husband James and son Harry.
Part of this was not only putting the Potter Family under the Fidelius but also hiding and protecting the lives of those of her sister and her husband and son as well. While not everyone knew how close the Evans sisters were, if you were to find one eventually you will find the other.
Albus contacted the unspeakables personally, untrusting of the Ministry as he knew Death Eaters had infiltrated almost every corner and department. They weren’t usually the department to handle such things, Magical Law Enforcement was, but they were best at the spells needed to do what needed to be done. The unspeakables were unwilling to help at first until Albus, knowing they could not expose what he would tell them without exposing themselves, told them of the prophecy.
They could see the importance of hiding both the Potters and the Dursleys and so were willing to help. Anything to rid the world of Voldemort.
And so while Dumbledore carefully placed the remaining three Potters under the Fidelius charm, a team of Unspeakables snuck into the Dursley home to begin their work. Having already fixed the memories of James and Lily’s close friends, all that remained were Petunia and Vernon Dursley. Dudley was of no consequence, being too young to remember anything of significance anyways, it was dangerous to mess with the mind of a child so young, lest you cause permanent damage.
It wasn’t too hard, really. With both of the Evan’s parents gone, it was much easier to concoct memories that didn’t exist, as there was no one around to contradict them. They didn’t have to be particularly strong either, as there was no plan on the Potters being in hiding long. Not many people would go looking for Petunia and that’s what the unspeakables, and Albus, wanted.
They carefully picked out memories and replaced them with imagined ones. Instead of Petunia being a muggleborn witch as well, she was now a muggle who never had any magic of her own. Memories of jealousy and hate brewing as she wished she could be of magic too. And eventually, that hate grew stronger than the bonds of sisterhood as words like “freak” echoed throughout her memory. Petunia Dursley hadn’t spoken to her sister in years, at least that’s what the unspeakables put in her mind. They hadn’t said a word to each other, not even a letter, since before Lily had graduated. It was done.
With Vernon it was much easier to manipulate his memories. Being an actual muggle, his mind was automatically less defended and so easily malleable. Additionally, he hadn’t met Petunia until his mid teens and any good memories of Lily and James and their friends were easier to turn into bad ones as they had only known each other for a few years. Of course they hit a few snags here and there. Memories of Dudley using accidental magic would pop up and would quickly need to be squashed. They couldn’t have the child of two magic hating muggles using magic after all.
It was done quicker than they had thought possible and, with the Dursleys still sound asleep but with their lives forever changed, they quietly snuck out the house.
Of course, these actions would have unforeseen consequences. Though no one would truly know what they were until it was too late.