Do you know about the Tales of Beedle the Bard? According to Julia (I didn't know) it has to do with these three brothers who encounter a river previously uncrossed by mortal men. They fool death or build a bridge or something and survive and get wishes. One asks for a powerful wand, one wants to bring back the dead, and one asks that Death not be able to follow him.
This results in the existence of the famous wand, the stone of Ingreness ... no wait, the Resurrection Stone, and the Invisibility Cloak. This is an oversimplification.
The stone actually turns dead people into zombies, the wand creates deadly hubris, and the invisibility cloak was not so dangerous, and that brother lived to an old age until he finally got tired of that gig, passed the cloak on to his offspring, and walked away from life arm and arm with death.
Harry Potter, it turns out, is related to these brothers, and the various objects ultimately would end up in his possession. This is an oversimplification. The night before Harry got his scar -- the night his parents were killed by he who shall not be named --- Dumbledore absconded with the invisibility cloak to study it.
Anyway, this fictional book turns out to really exist. JK Rowlings has written it, apparently, and it will be on sale in early December. You can preorder your copy by clicking on the book above.
Or, if you are a total Harry Potter Nut you can order the special collectors edition for a mere one hundred bucks, by pointing at your computer with your magic wand and issuing the following spell:
You actually scooped GrrlScientist with a Harry Potter story? You are indeed a powerful wizard!