The letter

"Alarick Von Stein. Master of the vampire kingdom of Europe. My Father or so I thought.

I was a half breed, what they hated most. When a vampire has a child with a witch or wizard."

Warnings:
- There is blood mentioned in this book (it's about vampires, kinda obvious )
- There will be sex scenes

In terms of when it's set it would be in Fred and Georges sixth year but events from the harry potter books are not present.