'If this is to end in fire, then we shall all burn together.'

William Parry stood before the forge in his dimly lit workshop, a rack of tools to his left and a heavy iron anvil to his right. The room was spacious, panelled with wood and the walls lined with worktables fitted with vices and drills. The day was drawing to a close and the last of the sunlight crept through the dirty windows sat next to the heavy wooden door, which was barred shut. His dæmon, a midnight coloured cat named Kirjava, sat quite still next to him and gazed into the dimly burning coals in the pit of the forge.

Will had dedicated the last seven years of his life to blacksmithing and was heavily built as a result. His chest and arms were broad and thick from the daily toil of shaping steel, his palms calloused and his fingers blistered. He had poured his blood, sweat and tears into this small forge in the middle of nowhere, and always remembered the night he, Lyra and Iorek Byrnison had repaired his knife for the first time. He wondered if Iorek was still alive, and what he might say if he knew that Will was about to try and do it again.

He thought of Lyra and the fire in her blue eyes, and her heartbroken face when he'd stepped through the window from her world and the botanic gardens, and the last time he'd ever gazed upon it. His heart fluttered and Kirjava purred briefly, nuzzling his hand. He wiped away a bead of sweat from his forehead and took hold of his shovel. He dug deep with it into the large coal bin in the corner of the room and carried a load over to the furnace. He sprinkled it over and mixed it with the lumps that were already burning below. He pulled down on a rope above his head which was fixed to the set of bellows on the other side of the brick pit, by wheels and pulleys. The flames roared and the fresh coal caught light.

Several times he repeated this process, until the forge was as hot as he knew he could make it. The flames in the middle of the coals danced in shades of blue, white and red as the jets of air hissed through the holes in metal piping deep within the fire pit. He had already laid out the fragments of his broken knife on an old green cloth on a worktable near him. The rosewood handle was cracked and blackened in places from the last time it had felt the heat of the forge. From the handle there protruded an inch or so of jagged metal, longer on one side than the other. He had spent years meticulously arranging the other eleven pieces in what he knew to be the right order, which he now knew by heart.

He knew every crack in every shard of the subtle knife like the wrinkles and scars on the back of his hands. They were as much a part of his being as his beating heart, his dæmon Kirjava, and his love for Lyra.

He had tried to be cheerful and to think only of the wonderful times they spent together, however brief they were. But when he had closed the window between them, a piece of his soul had been ripped from him just as when he'd left his dæmon behind on the shores of the dead. A sickness had taken hold of his heart and he knew that nothing, save but one thing would relieve him of it. To see Lyra's face again, to touch her skin and kiss her face and to hold her close until his heart was light and free again.

He forced himself to cast her out of his mind, for he knew while he repaired the knife his concentration must be unwavering, absolute. He had repaired countless knives in preparation for this night, thousands of blades he had shattered with ice and steel and meticulously remade. Though he knew that the challenge of this was nothing compared to what he must now do. He knew it would be easy, rejoining the shards of Æsahættr, but to create an edge fine enough to take him across the boundary between worlds would be the hardest thing he had ever done, even when he had done it once before.

He turned down to look at Kirjava and into her amber eyes, and the bright fires of his forge danced across them in reflection. She spoke softly. 'Are you sure you should do this?'

'I've never been more sure about anything in my life.' He replied, and picked up his heavy iron hammer. With a pair of metal tongs, he picked up the handle of the knife and the first shard and placed them both the middle of the burning coals, so the metal was buried in the hottest spot. He pulled down laboriously on the bellows and the flames roared. He pulled down and let go the rope a dozen times until the metal was white and scorching. The blasting heat broke over his face like a wave, stinging his skin. He took out the pieces with the tongs, which had cooled slightly to a deep shade of ruby red, and placed them overlapping onto his anvil.

Twice he struck the join with his hammer, and the edge began to take. He flipped over the knife and struck it twice more. Back into the flames he placed it, and pulled down on the bellows again until it was glowing. Onto the anvil again he took it and hammered it with two precise blows on each side. In his mind he felt the impact of the hammer on the knife and it shook him to his soul. Kirjava sat as still as ever, watching every hammer blow send sparks fly up and dance out of existence. Her eyes never blinked, her gaze never leaving the ever firmer join between handle and shard.

Will watched it too, feeling with his mind something he hadn't felt since he last cut open a window to his own world. The feeling of looking and not looking at the same time, like when you can see some things better in the dark from the corner of your eyes. Feeling for the edge of the blade with his mind, he focused on balancing it absolutely but gently, and he knew what it meant if he did not keep it perfectly in line.

After a short while of gently hammering here and there, the first piece of the blade was reattached. He did not pause for breath before he plunged the next two pieces into the heat of the forge and pulled down on the bellows. He took them both out again and aligned them on the anvil, striking them with heavy blows while he fixed the edge in his mind. For the next several pieces he repeated the process and it was not long before his muscles ached and his hands were beginning to burn. He'd completed about four inches of the blade and still had three pieces left, which included two shards the size of his thumbnail and the tip which took the shape of a diamond and would fit within them.

The coals were beginning to burn out to ash, so he took another shovel full from the coal bin and heated them until they were searing hot once more. He placed the knife back into the hottest spot along with the last of the shards and smashed them into place with a few strikes of his hammer. He fixed his concentration on the join in the blade and felt every atom quiver while he brought his fist down onto the steel. He turned the knife and looked down upon it from the side, which seemed to be straight to his eyes. He gazed at the unfinished knife, now with only the tip left to join back on.

He knew he was never supposed to do this, but the pain in his heart was too great to stop now. He did not know how much time had passed since he began, it could have been years; it could have been minutes. All he knew is that he had to complete it before he lost himself among his thoughts. Summoning all of the strength he could muster, he plunged the final pieces into the flames and pulled down on the rope. His hands were blistered, his arms ached and his back felt broken. Every tug of the rope, every spark that struck and burned his skin he cherished. Every bead of sweat that rolled down his face and his back he gladly gave so that the knife would be complete once more.

With what felt like the last of his energy he pulled the pieces from the inferno and hammered the tip into place. He remembered the roar of Iorek Byrnison in the cave; Hold it still in your mind! You have to forge it too! This is your task as much as mine! With the great bear's words swimming around his head he held it and kept hammering. Each blow upon the iron shot a pain through his head behind his eyes, but he did not break for a second from the state of mind he needed to forge the knife to end all knives.

After what seemed like a lifetime, the subtle knife sat smoking on the anvil, and Will dropped his hammer which landed with a loud thump on the stone floor below him. The handle of the knife was black and charred, and looked as though it may turn to dust if he touched it. The cracks between the shards of the hot orange blade were clearly visible, like scars across the desert. Will knew there was one last thing to do, and he poured yet more coal over the embers of the forge and cranked the bellows until they were white hot again.

He gently placed the completed knife over the flames and pulled with all his might until the blade shone from orange, to ruby red, to white. He felt like his muscles might give way and he'd never be able to pull down on that rope again, then an image of Lyra burst into his mind and overcame every sense he possessed, the smell of her hair like honey, the touch of her skin so smooth, the sound of her voice echoing I love you, and he knew he would be with her soon. At the moment she erupted into his mind, the surface of the knife sparked and exploded into colour, into midnight purple, swirled around deep blues and greens and ebony black, he saw the edge turn from black to silver to brilliant white and then it was translucent, a rainbow, and he could feel the keenness in his very soul. He took the knife at once and plunged it into a barrel of water. The water spat and boiled, then slowly bubbled down. When it had settled, he drew the knife out of the water and took it with his hand.

He turned over the familiar knife in his hands, and inspected it. The rosewood handle looked as though it would fall apart any moment, and the gold inlay had all but melted away. The blade itself was now around six inches long, much shorter than when he'd first acquired it. But much had changed since then, and this was no exception. Kirjava spoke for the first time since they had started. 'Is it sharp?' She asked.

Will nodded and with a fluid motion, drew the knife towards and straight through the anvil. The solid iron fell in two, one half tumbling to the floor. 'Yes,' He said, placing the knife carefully into its sheath. 'It's done.'