When Harry Potter and his twin sister Persephone were 3 years old, their parents, Lily and James Potter, were killed in a robbery gone wrong. It was on the day when they were transferring their small staff to a new set of owners. The manager told the police about the Potter children.
About how they always spent time with their godfather and presto uncle. They gave the address of the place they thought Sirius was staying.
But here's the thing, Lily and James Potter had faced dozens of death eaters and had faced Voldemort himself during the war and hadn't been killed by them. But they were killed while working their last day in their muggle grocery store.
The mugger was wounded and apprehended by a officer trying to get himself something to eat and drink so he could go back out on patrol. The Potter twins were both with Remus Lupin and Sirius Black eating their lunches when this happened.
That night, after Sirius and Remus were told, was rough. And on top of it all, it was a full moon. The first one without James since Peter betrayed the Longbottoms to the dark lord two years ago.
They had to get their neighbors, Helena and Ryan Granger, to watch the twins for the night. They were happy too seeing as their daughter, Hermione, loved spending time with the Potter twins. Hermione was happy when she saw her friends walking through the door with a sleeping bag and backpack each.
The next morning when Sirius picked up Harry and Persephone, Hermione had a bout of accidental magic. Sirius knew it wasn't his kids because he taught them control like his mother had with him and Regulus. So Sirius panicked.
Sirius did not know what he was supposed to do in this situation. But after a couple of deep breaths, Sirius eventually calmed down and told Helena and Ryan about Hermione's magic. About how she was, what the wizarding world he lived in called, a muggle born witch.
He also told that some people in the British wizarding world didn't like muggle borns much because they thought muggle borns were weaker or less important. But in America, muggle borns basically "rule the world" so to speak.
Two weeks later Remus and Sirius sold their house, sold the Potter house and moved themselves and the kids to New York. They moved into an apartment located in Queens New York. Their neighbors were Ben and May Parker along with their nephew Peter.
Peter had lost his parents due to OzCorp two years ago. The four adults couldn't separate the three children. They all seemed to be attached at the hip. A month later Sirius came home to see someone moving across the hall.
And being the nosey bastard he is, Sirius took a look in. What he saw shocked him a lot. What he saw was the people who he thought that he left in England. Helena and Ryan Granger with little Hermione running around.
When Hermione saw him, she squealed loudly with happiness. She quickly ran into Sirius's warm and tight embrace. Helena and Ryan turned to where their young daughter ran too. They saw Sirius hugging Hermione with a smile on his face.
That day was when Harry and Persephone introduced Hermione to Peter. The group of four were always together. They were the best of friends. They were always together either in the Granger home, the Parker home or the Black-Potter-Lupin home.
Over the years the quartet became closer and closer. They all went to New York City school of magic when they were 11 years old. A school was just like muggle public schools. They all had the same schedule.
Hermione would sit next to Harry in class and Persephone would sit next to Peter in class. The girls didn't want the boys to get into trouble a lot. And Harry and Peter had a tendency of talked when they weren't supposed to.