INFORMATIONS:
-20 years in the past-
First Serenity Gaunt is a cousin of Merope Gaunt. She was living in France but when her parents died she went to Hogwarts to start her education. There she met Abraxas Malfoy, Orion Black, Andrew Lestrange and Edward Rookwood. She became best friends with them. At their seventh year a prophesy had been made. Serenity got pregnant from Abraxas, Orion, Andrew and Edward by an ancient spell. The baby had blood from all of them and that made her powerful. Serenity died one year later from heartbroken because she had sent her daughter to the future.
Orion Black two years later married Walburga Black and together they had Sirius and Regulus Black.
Abraxas Malfoy later married and had a son named Lucius Malfoy.
Andrew Lestrange got married and had two sons, Rodolphus and Rabastan Lestrange.
Edward Rookwood got married as well and he had a son named Augustus Rookwood.
-20 years in the future-
Kenna-Alice Gaunt their daughter took the name Hermione Jean Granger from the muggle family who took her in after she was transferred 20 years into the future.
When Hermione found her true identity being a Gaunt and have for fathers Abraxas, Orion, Andrew and Edward, she learned that she had some brothers as well.
Lucius Malfoy, Sirius and Regulus Black, Augustus Rookwood, Rodolphus and Rabastan Lestrange are Kenna's brothers. They didn't know about that until her fifth year when she learned everything.
I hope this prologue will help you to understand few things abou the story! Forgive me for not putting it earlier!