A/N: some of the ages and birthdays in this story may be slightly different. I do not own Harry Potter (or the Kane Chronicles). Mrs Cooper is just a random muggle I made up. It is also slightly au because in this story Sirius does not go to Azkaban.
Prologue
28th July 1967
It was a hot summers day in muggle London and Mrs Cooper was doing her Saturday morning shopping. She was just finishing her shopping, and was walking out of the grocery store when something slammed into her, causing her to drop her bags.
"I'm awfully sorry Miss," said a young boy, "I didn't mean to hurt you." He began to help her. When everything was picked up, Mrs Cooper took a proper look at the boy. He looked about eight years old with black hair and sparkling grey eyes. Tugging at his shoulder was a smaller, skinnier, very anxious-looking boy, who otherwise looked exactly the same.
"Come on, Sirius, Mother will see us," whined the smaller boy, pulling harder. "We have to go now!"
"Sorry Mrs Muggle person, we have to go now," the older boy said hurriedly. The two boys continued running down the street.
"SIRIUS! REGULUS! COME BACK HERE NOW!" Mrs Cooper watched as a woman about her own age with black curly hair ran past her and caught up with the boys. She pinned the younger one against the shop wall and began shouting at him.
"How dare you talk to that muggle! She is nothing but filth! Do you want to disgrace your entire family?"
"I didn't!" the boy whimpered.
"It was my fault. I made her shopping go all over the floor," said Sirius.
"Silencio!" The woman pointed a small wooden stick at the elder boy. "Now tell me why you decided to run off like that," she said to the smaller boy.
The little boy, who couldn't have been older than five or six whimpered but did not say anything.
"Tell me now!" shouted the woman holding the stick to the boy's throat. By now a small crowd was starting to gather around to watch. Mrs Cooper watched in horror as the woman muttered something that sounded like "Crucio" causing the small child to scream and his whole body to shake violently. She ran inside to call the police.
"Siri help! Make it stop! Help!" the child was screaming. The woman kept pointing the stick, which looked like a wand, at him.
"Mother! Please stop your hurting him." The woman didn't lower her wand, and both children continued to shout out each other's names.
After about ten minutes or maybe more, the woman finally stopped. She shouted something that Mrs Cooper couldn't quite make out. A jet of white, blinding light shot out of the end of the wand, and hit Regulus, who was by then lying on the ground shaking. When the light had gone, the boy was no longer there. He had completely disappeared!
The other boy, Sirius, began shouting at his mother, while she attempted to drag him away from the scene. Cries of "What have you done?" and "Where is here?" and "Mother, I hate you!" could be heard as the woman tried to pry the boy's hands away from the drain pipe on the corner that he was clinging desperately to.
While this had been going on, the Ministry of Magic had received a call from the muggle police concerning misuse of magic and child abuse. A team of Obliviators, Aurors and a healer, were sent onto the scene.
Mrs Cooper watched in amazement and horror as a large group of people in cloaks arrived, riding on broomsticks. After they had dismounted the brooms, they started to run towards the confused crowd of people. Some ran straight to the woman and stopped her from hurting the boy any further. Another started to comfort the little boy, who had started sobbing uncontrollably and was now rocking backwards and forwards and mumbling his brother's name.
The remaining people walked towards the staring crowd of people, their wands raised. One, a man with dark brown hair and blue eyes, stood in front of Mrs Cooper.
"Obliviate," he said. Mrs Cooper felt dizzy for a moment and then looked around her. The crowd was beginning to disperse. She remembered there had been a street magic show on in the street. Mrs Cooper went home, and never thought about the two boys and their mother ever again.