I made the prologue as a prompt for hpfanfiction on reddit, but my brain wouldn't let me go after that. So here is my first foray into Harry Potter Fanfiction
Prologue
Letter found on Harry's pillow on his 11th Birthday
Son,
I'm writing this letter 2 months before you're due to be born, and I hope to be able to burn the letter in a couple of years and teach you what you need to know myself, however our family history suggests that may not be possible. You have grown up in, or are about to join, the magical world. As you have just reached the age where your magic stabilises, I need to tell you some things. The information in this letter cannot be shared with anyone else outside our family, and not even your father knows this information though he does know some of it as does every magical through fairy tales. I hope that by the end of the letter you understand why you can't talk about it to anyone that isn't related to my Great Grandfather by blood.
You may have noticed that there are no truly nocturnal magical creatures, even the owls sleep at night. This is because our world is not alone in space, rather it is accompanied by a myriad of other worlds that breach the aether every night during the witching hour. My great grandfather theorised that it was to equalise the magical pressure across the worlds, but what's important about this is that all magicals that are awake are carried along with this flow while their personal magic is active. What does this mean? Magic is active when it's being used, and while we are awake, we are always using magic. Our magic only becomes quiescent once we sleep. I could never tell her, but once I found out about our family, I always envied my sister for her lack of magic, for her ability to go out all night and come home at dawn. The thing is that while you'd think that you could just power through and tough it out for an hour, magic doesn't work like that. Time is not linear, especially when magic is involved; and the further into the dream, our name for what happens, the more magical the worlds become and the less hospitable to our worlds life it becomes. Because of this it's possible to experience a lifetime in the dream, if you can survive that long. Once you spend any amount of time in the Magical world, you start to hear about the odd disappearance. It's always the same, someone disappears from their room at night and is never found again.
Why is all of this important to us? It's because of Great Grandfather. He was what is called a squib, that's someone that's magical, but not magical enough to use a wand. He considered himself to be somewhat of a scientist, and in 1895 he read about an experiment where dogs were prevented from sleeping. On the 23rd June he met your Great Grandmother during the experiment and managed to bring her home. They had 4 children together, your Grandmother Trudy was the youngest and a miracle child born in 1918, Twins Simon & Fredrick were born in 1899, and Susan born in 1903 were her siblings. Simon and Fredrick were both conscripted during the 1st world war and disappeared some time during a sustained bombardment in 1916. They were marked as AWOL, though their companions claimed they just disappeared in front of them during the night, but the doctors said they were just suffering from shellshock. Susan married and had one child at the age of 20 in 1923, but she disappeared from the marriage bed with her baby 8 months after it was born. Your Grandmother married late in life to a doctor she met at the tail end of world war 2. I was born in 1959. My Mother died in childbirth, and your Grandfather remarried and had Tunie. Because of your Great Grandmother, our magic doesn't automatically become quiescent when we sleep, rather we need to feel safe and unthreatened.
As children this isn't a problem as our magic isn't developed enough to be active except under stress, however you are now old enough that you need to learn how to feel your magic and then learn how to coax it into quiescence even when you're stressed. You need to start learning now before you reach adulthood as the changes you'll be going through in the next few years will also change your magic into that of an adult. I've asked your Father to give you my journal, it's blood locked to my line so only you or your children will be able to open it. If for some reason he is unable to give it to you, get a book on Meditation that doesn't use a breathing technique, or a book on Occulumancy and don't move on from calming your mind until you've found your magic. You should then be able to learn how to make your magic quiescent.
From your loving Mother
Lily Potter.