A/N: Thanks for putting up with the long wait. Unfortunately, life sometimes gets in the way of fic writing. Don't you hate it when that happens? Anyway, a warning for this chapter: it gets a bit raunchy around the middle, though there really aren't any details, just things being implied. But here's a warning anyway. And sorry for all the Macbeth references. They kind of got away from me and became a little three-chapter arc. So I apologize if you've never read it before, but I think the important references are explained in here anyway, so you should be good.

Rule Eight: Know when you're being watched and who's watching you.

"And you will call me if you find anything, Detective?"

Dean turned around, gave his sincerest smile, and lied through his teeth. "Of course I will, Ma'am."

The disheveled woman with knots of light hair and watery, mascara-bleeding eyes sniffed and stepped off of her front porch and back into the house. As Dean walked purposefully past the identical square houses to the Impala, parked on the side of Suburbia Lane, he made a mental note to call his father. Another teenage boy dead in his bed, no medical problems, no sign of struggle, no nothing. Well, nothing except wet sheets… but then again, it was a hormonal teenage boy's bed. Nothing special there.

As he crossed the end of the driveway, a light breeze ruffled the upturned collar of his leather jacket and a chill tingled at his skin. Then, faint and whisper-like—the way that déjà vu feels—he knew, just knew, that a pair of eyes was following his every move. Slowly and deliberately, he turned in a full circle, scanning the area with a well-trained gaze.

Nothing.

Clear, sunny sky, green grass, pleasant white houses. Nothing out of the ordinary.

Giving himself a mental shake, he let the feeling roll off his back and away from his brain.

Sliding into the driver's seat, Dean revved the engine and pulled away from the nauseatingly normal chunk of Suburban life that he had entered as if in the Twilight Zone. Sometimes all those perfect square houses gave him the creeps.

As he drove he wished idly, and not for the first time, that his father was with him. True, John Winchester was only the in the next down for a day or so to cover more ground in the research phase of this hunt; still, with the empty passenger seat, he felt light-years away. And Sam—17-year-old, senior-in-high-school, homework-obsessed Sam—he was back home doing some crap essay.

It wasn't the first time the three Winchester men had been separated for a few days, but damned if Dean had gotten used to it. He liked his family together, as a whole, a trio taking down demons, thank-you-very-much. That's what it had been a couple of years ago, too. Before Sam's rebellious streak had sprung from the subliminal seeds of school and friends and "normalcy." Whatever that was.

The sky, being sliced through by the orange sun like a stick of butter relenting beneath the sharp blade of a knife, was splashed and speckled like an abstract painting. It seemed the entire light spectrum—what was it, ROYGBIV?—had decided to make an all-star appearance for that particular sunset. Red, orange, yellow, green, blue, indigo, violet. It was a poet's dream come true. Dean wasn't really that fond of sunsets.

And then there it was again, that odd sensation of two eyes burning a hole in the back of his head. His eyes flicked up to the rearview mirror, but the backseat was empty. Sighing in frustration with himself, he cranked up the Metallica as "Until It Sleeps" blasted through the speakers.

The road stretched bleakly ahead, the neighborhood swiftly turning from neatly manicured lawns to gas stations and roadside bars. The sunset didn't seem to be quite as luminescent in this neck of the woods. Those kinds of things never were.

At long last, Dean pulled the Impala into the tiny parking lot of the nearby fleabag motel. As his boots met the asphalt with a tap, his eyes swept the area for signs of life. There were none. Yet that creeping feeling of predatory eyes piercing his body remained. He turned a full 720 degrees before once again scolding himself for paranoia. All he needed was some shut-eye.

No, what he needed—and of course, would be loath to admit this—was some company. Of course, he'd spent the entire day talking to a wreck of a mother whose son had just died and two stoned teenagers who had been his friends, but that kind of company was about as welcome as dirty socks on a dinner plate. What he needed was someone from his world; and there were only two people like that. One was currently sitting around at home working on some stupid homework assignment, and the other was in the next town doing his own research.

After adding another 360 degrees to his 720, Dean finally dug his hands into his pockets and produced the room key, trudging across the parking lot to room 11. It took all his greatest efforts not to spin around several times when the feeling of being watched intensified. Coward, he thought to himself. Your dad and little brother leave you alone for five minutes and you're already imagining things.

Once inside the room and feeling more at-ease, Dean tossed his jacket onto the nearby table and flopped down on the bed, allowing himself the luxury of a long, heavy sigh. He regretted not stopping for a beer. Hey, at least he was old enough to legally drink it, now.

Idly—more to have something to do with his hands than anything else—Dean reached off the edge of the bed and pulled his duffel bag up onto the questionable mattress. Rifling through it, he found a pair of worn and torn jeans, two shotguns (which he laid out carefully on the bedside table), a toothbrush that had clearly been through the mill, a knife (which he tucked under his pillow), and two books. One was a notebook filled with scraps of information on their current hunt—his own temporary emulation of his father's journal. The other was the faded and weathered copy of Macbeth that he had bought Sam a few years ago for school.

He hadn't told Sam that he'd taken it with him—hell, he'd never even admit to Sam that he'd already read it. Twice. That was information he'd take to the grave, or crematorium. Otherwise Sam would have jested for days about how he'd thought Dean was illiterate.

Flipping through the first couple of pages, not really sure of where his meandering fingers would take him, Dean skimmed several passages. He wasn't really sure why he liked this book so much; after all, reading wasn't exactly his favorite activity in the world. But good ol' Billy Shakespeare… he knew his stuff. It was a classic tale, really; murder, betrayal, a couple of badass witches—the works. But mostly it was about a guy falling victim to the persuasion of the supernatural and descending down the path of darkness through the shedding of human blood. A soldier going from killing on the battlefield to killing his best friend.

There was often a fine line between soldier and murderer; hunter and monster.

Though Dean didn't really like to think about that line too much.

Dropping the book back into the bag, Dean sprawled out on top of the covers, leaning back and closing his eyes with his hands folded neatly under his head. Visions of Banquo's ghost, the dead boy, three witches, and the weeping mother swam erratically through his inner eye. At last, Dean was all arms and legs hanging everywhere on the bed as he faded in and out of fitful unconsciousness.

It was the soft caress that shocked him from his dream involving a showdown between John Winchester, Lady Macbeth, and a vampire that looked oddly like Sam. Mind in a haze, he gazed through the darkness above him, but there was nothing there.

"Dean," a soft, seductive voice whispered in his ear. It sounded both familiar and unfamiliar at the same time. Which was odd in itself, but he was too groggy and disoriented to notice.

The touch returned, so soft it was like liquid, or a gentle breeze gracing his face and neck. It was soothing, like the hiss of the ocean current washing ashore. He fell into a lull of security as the breeze blew over his mouth, turning into warm breath before lips, soft as rose petals, pressed against his.

By time the unseen lips moved away, Dean knew how far his invisible intruder wanted to go. Yet her identity remained a mystery, as his mind was too foggy to fully comprehend the possible complications of this visit. All he knew was that a feeling of total contentment was filling within him, of belonging… he was with someone, someone who understood him… he was not alone.

The temptress pressed into him, the curve of her darkness fitting nicely with his body like a puzzle. His breathing quickened, and all he could think of was how right this felt. And then she deepened in another kiss, and he felt suddenly as though his remaining energy were being sapped through his mouth. But he didn't care. As long as she was there with him and he wasn't alone.

Light, willowy fingers ran through his short hair, splaying out on the sides of his head as she lowered herself once again.

Dean moaned.

She kissed him again, and he tried to kiss back but was practically paralyzed by the sensation of energy simply pouring out of his mouth. It was as though she were sucking him dry, breathing in his life as he grew more and more tired and confused.

But she was still there with him, and it didn't matter.

She was there, unlike any woman had ever been for him. Not his mother, not any ten-minute girlfriends or one-night stands. She was there. With him. And she wasn't leaving.

But he found it difficult to move at all anymore, his heart thumping wildly in his chest as he realized just how truly exhausted he was. Perhaps he and this mystery woman should call it a night. He needed sleep so that he could get up early and work on the hunt.

The hunt.

And he thought of his dad, and Sam, and that dead boy, and the weeping mother, and he realized that he was asleep.

Dean's eyes flew open as he woke up, panting and sweating, and when he gazed into the darkness above him, there as more than darkness.

There she was, the mysterious—and no longer invisible—woman: crouching over him, skin pale to the point of ethereal translucence, billowing ebony hair, a smile like broken glass, and darkness swimming tauntingly and seductively in her calculating eyes. Her touch was still soft like liquid, but now, with the comprehension of consciousness, there was something eerie about the way she blew over him like a gentle breeze.

And in the darkness of her eyes, he could see himself.

He could feel that scorching gaze slicing into his skin, burning him and bleeding him dry, as she whispered, "I've been watching you, Dean."

For the briefest of moments, as he gazed into her reflective eyes—it was him, him in the darkness, alone in the darkness, with the monsters in the darkness and grinning—, he hesitated. And then he reached swiftly under the pillow beneath his head and withdrew the knife. In one deft movement, he slashed the knife before him, and the blade caught her pearly shoulder. Black blood oozed from the gaping wound, and her eyes lit up with fire as a piercing, unearthly scream like that of a banshee wailed through the night.

A furious wind swirled around for a moment as she glared at him and fled the room. Dean dropped the knife onto the bedside table, breathing slowly and trying to stop the slight trembling in his hands.

It was now obvious to him, in the clarity of wakefulness, what had been watching him leave the boy's house and come back to the motel. And he felt like an idiot for not realizing it. Hadn't his father always told him to know when you're being watched and who's watching you?

But that was the least of the worry and fear coursing through him.

He had liked it. A monster—hell, the thing they were hunting right now—had taken advantage of him, and he had liked it. Had felt safe. Had felt content. Had felt wanted. And goddammit, how screwed up was that?

There was a fine line between hunter and monster.

The thought chilled Dean to the core. Macbeth had briefly been confronted by supernatural beings and had allowed himself to become a monster. Dean dealt with supernatural beings on a daily basis.

What would become of him when that line started to blur?

He thought of the man he had nearly shot a few years ago, the one in the bar—Shooter, ironically. But I wasn't really going to shoot him. But he had thought about it. Briefly, momentarily, yes. But he had thought about it.

And suddenly, the line wasn't quite so clear anymore.

Dean carefully controlled his breathing, willing himself not to get sick over the side of the crappy motel bed.

One-night stands were one thing. Ghost rape? Entirely different. At least with human women he wasn't dicking around with the devil. Except, was it really rape at all? Rape was non-consensual. He bit back more bile in his throat.

It would never happen again.

In the coming days, Dean would end up mentioning to his father that he suspected the teenage boys were the victims of a succubus sucking the life out of them through sex. His father would nod pensively. Then, later that week, they would find the bitch and take her down. And John Winchester would beam proudly at his son for putting the clues together.

But it would never happen again.

And Dean would never tell his dad about that night. He wouldn't tell anyone.

But the darkness he'd seen in the mirror of her eyes would continue to haunt him. Every time he glanced over his shoulder in a paranoid fashion, every time he clutched the knife under his pillow—he would see her. And he would know when he was being watched by something so that it would never happen again, because he couldn't bear to witness the darkness obscuring that fine line between hunter and monster. And it was a very fine line indeed.