It was watching when they returned home that night, lurking silently, its invisible tendrils spread throughout the winding corridors and myriad rooms of the bunker, so that it seemed that every shadow had eyes. And they felt it instantly - every undulating shadow was somehow darker than it ought to be, every grating squeak and muffled thump of the old bunker seemed imbued with a subtle menace that had never been there before.

But it was their home, their one place of safety in the midst of a world of terrors, so they wrote it off to a few too many late nights and a little too much alcohol, because after all, this place was built to keep the horrors out. It was impenetrable by design, and whatever they thought they heard, whatever they thought they saw that set the hairs on the backs of their necks on end, it had to be no more than their imaginations.

Still, Dean found himself shivering inexplicably as the bunker door clanged shut behind him, the sound that had until now signified protection and relief now seeming to echo throughout the bunker as a sort of a death knell, and then dying off into a silence that was somehow too still, an eerie quiet broken only by the sound of their footsteps.

And though he would never have admitted it, he could not shake the fear that crept inside his heart, the sense of dread that the shadows instilled in him, and the chill that sank deeper into his bones every second. Dean Winchester, who was never scared of anything, was afraid.

In the shadows, it felt the slow crescendo of his fear begin, and it smiled, for there was no other scent so exquisite as the stench of men's fear, brewed slowly and surely to a terror beyond imagining.

It began by building its strength, flexing muscles that had been unused for seven decades, reaching out slowly to infect its victims with fear and despair.

Sam heard it first, a whispering that seemed to come from everywhere and nowhere, a voice that came out of the shadows, crooning to him in words that he didn't understand, but that made him think of darkness and dripping blood, of distant screams and the thrill of the kill.

It unsettled him more than he was willing to admit, and when the others couldn't hear it, he tried to pretend it was nothing more than too many years spent dealing with evil, and too many brushes with death.

But the voice continued to follow him, calling to him from the darkness. Sometimes it almost seemed that it was speaking his name, but he steadfastly ignored it. The bunker was protected from ghosts, from demons, and every other evil creature, and the new angel warding had been proven effective, so it could not be there.

At night, though, he couldn't escape it, for it walked his dreams, calling out his name, but always just out of sight and out of reach.

And when it grew powerful enough to fill his dreams with itself, with darkness and blood, it knew it was ready to begin the hunt, finally strong enough to stalk its prey through the cold, grey corridors of the bunker and compose grand stories of blood and pain.

Like every predator throughout the ages, when it came time to hunt, it began with the one it perceived as weakest - with the one whose fears and insecurities were closest to the surface, and easiest to bring to fullness. And it knew every trick for separating the weak from the herd - it had millennia of experience, and the blood of thousands on its hands.

It started with the lights, reaching out through the old wiring and dimming them ever so slowly, so that the shadows seemed to reach out with grasping fingers from every darkened corner and from under every bed. For it was one with the darkness, one with the gloom that crept silently inward. It was and had always been the unknown enemy waiting just beyond the light of the caveman's fire, the darkness filling men's hearts with fear and despair.

And Kevin felt it, an oppressive force gathering in the shadows, inching ever closer, slithering down the walls as the light slowly paled. It was the ghost of his dead mother, the pain of Crowley's torture, a woman's blood splattered and dripping down his face - all of his worst fears, the stuff of his nightmares, lurking in the darkness, waiting to consume him.

Then the lights went out altogether, and it was there with him, whispering to him of all the horrors it had planned, of the beauty of blood and screams and the sweet taste of terror.

They can't save you, it crooned, for the dark is mine now and forever, the blackness the empty page on which my stories are written. Scream, for you are in my story now.

And he did scream then, a scream that went on and on, as it cut into his chest, pulling the knife across his ribs one slow inch at a time.

It could smell the terror as strongly as it could the sweet scent of the blood pouring out in the wake of its blade, each beat of the boy's heart sending another pulse of red dripping down his chest, down the handle of the knife, spattering on the floor. The screams were like a symphony to its ears, a melody played to the beat of the falling blood and the pounding of a failing heart. And it was beautiful, oh so beautiful, the music of the boy's death. It was a pity it couldn't last forever, this magnificent amalgamation of fear and life and death and blood.

But there could be one final crescendo, one final climax before the boy's story ended forever, and when it sensed his end was almost upon them, that death was also moving through the shadows, it made its move. The lights suddenly flared back to life, and the wickedly curved blade flashed suddenly in the light as it flew upward, slicing through the boy's throat in a single graceful stroke.

And this, this was its grand ending, as it felt the blood spraying outward and watched his lips moving in soundless screams, as it looked into his eyes and finally beheld the perfect terror there, the fear and despair that can only be known on the brink of death.

Then the boy was dead, his story brought to its final beautiful conclusion, and for a moment it mourned his passing, because there was no more beauty here, no more fear or pain or despair, only nothingness.

But there were still more stories to write, and as it laid the knife gently across his chest, it was already planning its next atrocity, the new tale it would write on the walls in blood.

The angel would be next.