AN: While this is a crossover between Harry Potter and Garth Nix's Old Kingdom series, you won't have to know anything about the latter going into the story.
The waters of the Black Lake rippled with the wind, the trees of the Forest bending in their black and ominous ranks. A bright full moon shone down upon the valley, illuminating the cold stones of an ancient fortress and the silent wings of a hundred hunting owls.
It was nearly midnight in Hogwarts Castle, and there were three days left until Harry Potter would die.
Three days before he faced a dragon, with no plan, no power, no spell to save him.
Under his invisibility cloak, Harry paced the empty halls of Hogwarts, sifting through his exhausted mind for anything he might have been taught to help him survive the fight. Hermione had thought of the Summoning Charm, but that was no use; he couldn't even summon his broom across the Great Hall, much less to the arena of the task. Sirius' plan, whatever it had been, was lost when Ron came into the common room at the worst possible moment. Now, Harry was almost out of time, trying desperately to think of something, anything. Feeling morbidly thoughtful, inspired by something he couldn't quite place, he whispered a quiet phrase to himself as he walked past a tapestry of dancing trolls.
"For everyone and everything, there is a time to die."
As the last word passed his lips, a dim light and a rush of warmth filled the corridor. Harry jumped in shock and spun around to look at where the light was coming from.
"Bloody hell…"
Across from the tapestry, the stones of Hogwarts were shimmering with golden symbols, darting about like glowing birds in a grey sky. Were they runes? Harry hadn't taken that class. Now he regretted it. As he watched in awe, the symbols resolved themselves into an arched door, traced in lines of fire on the wall and glowing almost as bright as the sun - and it was making a sound. Hesitantly, Harry leaned closer to the door and pulled back the hood of his invisibility cloak to listen. It sounded like… like… he leaned even further in. His head brushed against the stone, and he heard what the door was whispering.
"Abhorsen!"
The door opened. In a whirl of silver fabric, Harry was pulled off his feet and hurled through. It shut without a sound, and the lines of fire that made it up dimmed to blackness. Nothing remained in the corridor but the night.
Harry awoke lying on something soft but slightly itchy. Dazed from his strange journey, he sat up and looked around the place he now found himself in. The room was round, its stone walls lined with wooden bookshelves and tall windows. An old-looking desk dominated the center of the room, its top lit by a few of the orbs of golden light that drifted aimlessly about. Meanwhile, the soft surface he had woken up on revealed itself to be a deep blue rug with a pattern of silver keys, sitting in front of a large but empty fireplace. Behind him lay a door that looked like the one in the corridor, except that it was very real wood instead of golden fire. Harry walked around the perimeter of the room, looking at the books and other objects on the shelves. Here was a painting, a dusty stack of parchment, an empty scabbard… Eventually, he came to the desk in the center of the room, and almost jumped off his feet with surprise.
On the desk was a book that hadn't been there before. It was bound in red cloth, with a title stamped in gilt. Harry couldn't read the letters at first, but as he examined it, they shifted into English, plain and clear.
The Book of Godric Gryffindor, Abhorsen.
"No way. Did Gryffindor actually write this?" he breathed. "This place has got to be ancient."
Excited at the prospect of a book written by the founder of his House, Harry turned to the first page.
I write these words in the hope that I may help another of my line take up the mantle of my work. My dear reader and Descendant - and rest assured that you are, or my study would not have appeared to you - I have carried a great duty all my life, which I must now pass on to you, for if this book has appeared, then my work will soon be needed and only you can carry it out.
Descendant, I am a necromancer, but I do not raise the dead. Instead, I banish and bind them for the good of Britannia and her people. I am more than a common mage as well, for I have been baptised in the Charter of Life. You are as well, Descendant, whether or not you know it - I certainly was never told, and I hope this book will help you if you are in my place.
Yeah, as far as he knew, Harry hadn't been baptised in much of anything. And what was a necromancer?
The first thing you must do if you would follow in my steps is to read The Book of the Dead. I do not know when it was penned or by what hand, but it set me on the path to my power and my arts, as it did for my grandfather Aodhan and his thrice-great grandmother Niniane. It shall be your greatest ally in this work we must perform.
The Book is in this library. If you are ready, you will find it. Begin to read it, learn the marks of the Charter, and take up the bells. Once you do, another part of my own book shall be revealed to you, and you will have stepped onto the path of the Abhorsen.
Yours in the Charter, Descendant,
Godric Gryffindor
A dazed Harry Potter set down the book.
He was a descendant of Gryffindor. He was a descendant of Gryffindor. Godric Gryffindor, the legendary Hogwarts Founder. What was he supposed to do with that knowledge? How could he live up to that?
Shocked by the news, his head spinning with disjointed thoughts, Harry walked back to the door. Thankfully, he wasn't thrown through it this time. Stumbling back to the Gryffindor dormitory, he collapsed on the bed and fell asleep.
Harry dreamed of a cold river, full of human shapes. All light was hidden under a heavy shroud of fog. Far in the distance, a waterfall roared, and at his back was a wall of mist. Harry didn't know how long he waited there, but after an interminable time, the sound of the waterfall stopped. At first in fits of sudden motion, then as smooth as oiled silk, a shadow rose up from the place where the rumble of the river had fallen silent. Towering over the water in a pillar of darkness, an aura of fear flared out from it like a cloak. Suddenly, the thing was coming toward him! Its approach sped up, it was getting closer and closer - Harry heard it laughing, a terrible sound like roaring wind and breaking ice -
Harry woke up in his bed, soaked with sweat. The area around his scar burned with heat.
All he could think of was that he had to find his friends.
I'm a new writer, so please review this and tell me what you think of it, or how I can improve. Thanks!