Demons are unique in one particular aspect, different from pretty much every other monster out there: they can't feel pain. They're immaterial, just like ghosts are, but unlike ghosts, they can't do a damn thing to the world around them unless they're in a stolen vessel. From what I understand about the lore, angels need permission in order to take over a human, but demons don't need anything at all to force their way in and do whatever they want. It's rape in its most fundamental form, and demons aren't particularly choosy about who their victims are.
Once they're wearing somebody's skin, demons can use all of their Lucifer-given power. Telekinesis, killing with a touch, teleportation, even control over fire and light, in rare cases. And they wear their vessel like armor. Take a swing at them, and it'll only knock some innocent person's teeth out, and the demon will keep on coming. Bury an ax in their chest, and the vessel will bleed out, but the demon won't even flinch. Shoot them in the head. You'll free the human soul that's been an unwilling passenger this whole time, but as for the demon, you might as well be throwing peanuts at it. They don't feel anything that happens to their vessels.
Demons react to iron, holy water, and salt with what looks a lot like pain, but I don't think it is. They can't cross over lines or circles constructed from these substances, so I think that they're just recoiling from it. It isn't even discomfort. Steam might rise from the skin of a vessel when you fling holy water at it, but there aren't any burns left behind. It's just a chemical reaction between the power of faith and the essence of the demon itself.
They can be hindered by an injury to whatever human body they're currently riding. They might scream and carry on when you throw a handful of salt at them. It's very easy to forget that nothing hurts them for real - but it's important not to.
Demons. Can't. Feel. Pain. Keep that in mind.
- Demons and Other Biblical Monsters, Sam Winchester
An intentionally protein-rich lunch was followed by a fifteen-minute power nap, after Sam was finished with Gordon and had discovered a new resolve sitting like a lead weight in his stomach. Any longer than that and he would have started sinking into a deeper sleep pattern, which would have left him more tired when he got up than when he'd laid down. He went straight from his bed into a cold shower, which ended up knotting the muscles of his leg but still felt invigorating. Long hair drying in dark strings around his face, he shaved and brushed his teeth. The normal rituals just helped to wake him up further.
Once he felt as clean as he was probably going to get, Sam bound his hair back into a stubby ponytail with a rubber band, then took a cushion out onto the front porch and meditated. There was a lot to be said for clearing your mind for a couple of hours, for breathing deeply and focusing. And there were so many ways to do it. Listening to classical music, like he had after his session with Elspeth, was one that worked particularly well for him when he was wound up far past the point of comfort.
When he was a teenager, he used to run, as a form of meditation. Especially after a fight with his dad. With how often they clashed during that period of his life, he must have logged over a thousand miles, on trails and sidewalks all across the country.
But, obviously, he couldn't really do that anymore. So it was this or nothing.
Sam felt incredible after spending the better part of three hours outside, eyes closed and legs folded beneath him. The thick forest surrounding his cabin meant an almost claustrophobic isolation, but it also translated to a deep peace and an endless supply of fresh air. His sense of positivity was through the roof as he took the cushion back inside and got out two pots and a half-empty jug of bleach. He felt great about the experiments that he planned on performing on the demon tonight, and thought that he might even be able to spend an hour or two with Elspeth when he was done.
Vaughn and Nadia got their dinner. Vaughn complained about impending boredom, since he didn't have much left to read, and then about impending indigestion, when Sam told him that this would be his last pig brain for a while. Nadia was naked. This was only about the twentieth time that she'd tried it on him, so he didn't spare her orange-sized breasts or the red designs that surrounded her dark nipples more than a passing glance. He twitched, interestedly and involuntarily, in his boxers, though, when she took deep, powerful gulps of blood and her chest bounced with the rhythm of them.
He really needed to get laid, Sam realized as he cleaned everything up. Eight years was a long time for anyone, even him, with his tame libido, to go without getting any. But, somehow, he doubted that Garth would be up for delivering an afternoon delight with his usual shipment of supplies.
The whole house stank of bleach. With everything else taken care of, there was nothing left for him to do but face the demon. Calmly, Sam took a flask of holy water from the kitchen, a cast-iron poker from the umbrella stand of blunt instruments by the door, and one of his older journals from the neat stacks underneath his bed. Then he unlocked the door and entered the demon cell.
The demon shifted as much as he could in his chair when Sam came in, moving his head in order to get a better look at him. His eyes were drawn down to what Sam was carrying, and then they flicked to black. The ghost of a smirk made Sam's lips twitch.
"Yeah," he said, nodding. "It's finally time."
He set down the flask and the poker near the gate, then walked slowly forward as he flipped through the book in his hands. He stopped when he reached the notes that he'd taken about experiments on a standard demon - black eyes, unassuming male vessel, pretty low on Hell's totem pole. This Knight had to be pretty high-ranking, but hey, he still had black eyes. So some of Sam's earlier techniques might work on him. Only one way to find out.
"'Unable to cross barriers of salt,'" he read. "'Line thickness doesn't matter just so long as it's unbroken...holy water produces steam and an apparent pain reaction. Vessel is left unharmed.'" He snapped the journal shut as he reached his usual place, standing several feet in front of the demon and his chair. The kindness he used with Vaughn and the healthy respect that he had for Nadia wouldn't work here, with this thing. His only option was intimidation.
The demon looked up at him, making unashamed eye contact. Speaking of eyes, his were still black. Sam had learned that that was because the black smoke that made up every garden-variety demon out there flowed through the pupil and flooded the aqueous humor - his theory was that it was some kind of threat display, since the eyes seemed to involuntarily change when their owner got splashed with holy water or caught by an exorcism ritual.
He shook that little bit of trivia out of his head and folded his arms across his chest, his journal still in one hand. It wasn't gonna help him here. He began, "This isn't personal."
The demon leaned back in his chair, tar-colored eyes hooding with skepticism. Sam continued.
"You might've tried to take a bite outta me, and you might've spit in my face." He shifted his weight from one foot to the next, but didn't move his steady gaze. "But that's not why I'm gonna hurt you today. I don't hold grudges - I can't really afford to, in my line of work." He leaned forward a little, which brought a twinge from his leg. "I'm gonna hurt you because the people I work with, people I care about, need information. If there are more things like you out there, then they need to know how to stop them in their tracks. So they can save lives."
The demon shook his head, plush lips twisting slowly into a smile as he did. Sam wasn't sure if he didn't believe him about the grudge thing, if he was denouncing everything that he stood for, or if he was trying to tell him that there weren't any other Knights out there. Just like he had told Gordon before someone crushed his throat.
It would be a waste of time to try and figure it out. Sam turned and walked back to the front of the cell, swapping his journal out for the poker and flask. The demon looked unimpressed when he returned to him, his barefeet and the hems of his jeans making a whispery sound against the runes that'd been chiseled into the floor.
"Gordon and his men," Sam said, before unscrewing the flask with his teeth. He spoke around the cap. "The ones who caught you?" He let it fall, clattering, to the floor between his feet, which were spread shoulder-width apart. He made a mental note not to step on it and look like an idiot later. "I'm guessing that they used a lot of different stuff on you." He shook the flask, which made the blessed water inside slosh loudly. "But they were just trying to get rid of you. They weren't experimenting, which is what I'm going to be doing here. They weren't watching you to see what hurt you the most." He raised the poker a little, into a ready position. "I just thought I'd warn you: I'm not like them, and this is going to hurt worse than anything they did to you."
Sam hadn't been expecting a reaction to his little speech, but the demon smiled widely, and bounced well-shaped eyebrows at him. The message was clear: Bring it on.
Sam did. He swung the flask in a tight arch with a fluid movement of his wrist, and sent a thin rope of holy water splashing straight across the demon's face at eye level.
His reaction was instantaneous. He jerked back and snapped his eyes shut, but even with the freakish reflexes of something that came out of hell, it was too little, too late. The water was in his eyes, running down his face, and steam billowed up from the pale, freckled skin of his vessel in sickly tendrils. He shook his head violently back and forth in an effort to get it off of himself. A sound of agony bubbled up out of his mangled throat, a broken, grating noise that probably caused him just as much pain as what he was trying to express.
Sam watched it all impassively, already tucking away observations that he'd need to write down later so that he could relay them to Gordon. He hadn't brought a book to take notes in because he knew that his hands would be full.
Something inside of him twitched and cringed, watching the demon try to scream, but he crushed it under the heel of the boot of his will. It wasn't real pain. It couldn't be real pain. The second that he started feeling anything like sympathy for this thing, the most dangerous demon he'd ever had in his home, then it was all over.
The demon recovered, after a few minutes of writhing and thrashing around (not that he could do either very well, with all the restraints on him). The few droplets of holy water that hadn't evaporated dripped off of his chin, their power cancelled out by what he was. His head was bowed slightly and his eyes had faded to green. They were fixed, sightlessly, on his lap, or maybe his hands. Sam started to cock his head, wanting a better view of his face and therefore a better clue as to what he was feeling.
Suddenly, the demon's head snapped up, his lips pursed, and a red projectile came straight at Sam chest. He reacted reflexively, neatly stepping aside. A mixture of blood and phlegm spattered noisily against the concrete of the floor. The demon's eyes followed him as he moved, face turning towards him. His lips were red and slick now. He must still be bleeding internally, or at least in his mouth.
"You're eventually gonna get tired of spitting at me," Sam said. The only response he got was a loud sucking noise, as if the demon was gathering more ammunition. Sam would really rather not dodge another stream of gore. His wrist twitched, sending a fountain of holy water tumbling down over the demon's bound hands, the fingers that had just barely healed. It all but emptied the flask.
The reaction was just as violent this time as it had been the last. Maybe even more so. His fingers were more sensitive than his eyes, obviously - or something else was, since the water on his hands was dripping down onto his lap and soaking through his jeans. The dried blood that covered his shirt was wet again, and it glistened in the light coming from the other room as he spasmed and bucked against his restraints. His freckled face twisted with hurt, but he didn't try to scream again, apparently having learned his lesson about that.
Sam, standing to the side of the chair, watched the demon's hands shake like an alcoholic wrestling with DTs. He clenched and unclenched them as tendrils of steam wafted up past his black eyes. Sam swallowed, a little too thickly for his taste. At least he knew that concentrated holy water hurt, even if it didn't incapacitate a Knight.
The pain slowly faded as Sam watched, the steam stopped rising. The demon's hands shuddered, then went limp, hanging from their cuffs. Sam tossed the flask aside. He knew that he'd have to pick it up later, but for now, it was all about making an impression.
He could swear that the demon flinched a tiny bit at the sound of metal clattering against concrete. But before he could start feeling triumphant, he turned his head towards him, fixing his black eyes on his face. Sam was shocked at how expressive they were, considering that they were a solid color. And he suppressed a shiver, at the hate he could see in them, the rage. It was intense enough to be...well, demonic.
Sam was so focussed on the demon's eyes that he barely noticed him lifting one of his hands again, curling it into a fist, and rapidly popping it open again. But he noticed when the rubber band that he'd used to tie his hair back, the brand-new, thick, sturdy rubber band, snapped.
Sam simply reacted as his hair, now loose, tumbled forward around his face. It was driven by panic. He didn't stop to consider that having his rubber band broken really wasn't that big of a deal, or that this was probably the full extent of what the demon could do with all those chains and straps on him. His mind zeroed in on the fact that he had to discourage that kind of behavior before it even really got started, and the poker came up, its tip pressing into a patch of vulnerable flesh on the demon's neck - above the bandage but below his hair.
He tried to pull away. Sam pressed harder, knowing that he had nowhere to go. Smoke curled up with an ugly hissing sound, and the pale skin turned reddened and puckered where the iron was in contact with it. Every muscle in the demon's body had gone as taut as the rubber band that had been wrapped around Sam's hair. His mouth was open in a soundless gasp, , and his eyes were wide - and still black. Sam noted, clinically, they looked glossier than usual, as he pushed the poker deeper and deeper into the meat of the demon's neck and the hissing increased. But he dismissed it.
Until, at least, what was unmistakably a tear welled out of one of his eyes and traced a path through the dried blood and grime on his face, before catching itself in his stubble.
Sam jerked the poker away. The demon went limp with something that looked a whole lot like exhaustion almost as soon as he did, head lolling to the side and exposing the raw burn that Sam had created. He blinked slowly, and tears kept leaking from his eyes as the black drained away, disappearing into his pupils.
His gaze flicked to Sam as the poker slipped out of his numb fingers and crashed, devastatingly loud, to the floor. His mouth twitched a little, baring blood-webbed teeth in a brief grimace. He squinted his eyes, as if trying to get himself to stop crying, then visibly winced in pain when the movement tugged on his wound. The tears on his cheeks reflected the light, just as the blood on his shirt had done earlier. He made a soft hitching sound in the back of his throat, and then Sam couldn't stand to be in the cell any longer.
He left the poker, the flask, its lid, the journal, everything that wasn't on his body as he bolted through the gate and away from the weeping demon. His leg screamed like the demon had tried to as he ran on it for the first time in seven years, and gave out after about a dozen strides, in the bathroom. It dumped him right in front of the toilet, which he grabbed and heaved into the second that he was on its level. His stomach had been climbing his throat the whole time, and he couldn't hold it back any longer.
Sam retched out the remains of his lunch. His eyes watered, sending tears streaming down his face, and he wasn't sure that they were all because of his gag reflex. He was sick from himself and what he had done. Sick from seeing tears of pain that the leader of a demonic army hadn't been able to hold back.
Sam's breathing shuddered and stuck when he was done, leaning heavily against the toilet. His cheek was pressed to the cool porcelain of the seat and his eyes were closed, a droplet falling every once in a while off of his eyelashes and into the mess in the bowl with an almost musical plop. Slowly, he raised a hand to tug the lever down, and lifted his head to gulp in fresh air as it flushed. He used his other hand to wipe the moisture off of his face. After rocking back on his heels, he got to his feet (or, well, foot - his left leg refused to cooperate), and leaned heavily against the counter. He washed his hands, splashed some of the cold water on his face when they were clean, then brushed pretty much his entire mouth to get rid of the acrid taste of vomit.
He stared fiercely at himself in the mirror while he did that, making eye contact, trying to get a grip. His irises were a watery gray right now; he had gotten used, a long time ago, to them being a different color every time he looked in the mirror. Not quite like a demon's eyes changed color, though.
He spat a mouthful of foam into the sink and turned on the water to rinse it away. It had to have been a trick, designed to manipulate him - and it'd definitely worked, Sam though with a humorless smirk to his reflection. Demons, in his lengthy experience with them, didn't feel pain that was in any way similar to what human beings did. They didn't shed tears. There were plenty of normal people out there who could cry on command, and he was sure that it'd be even easier for demons to squeeze out a few tears, with control over their vessels so great that they could stop hearts if they wanted to.
But, somehow, thinking about this wasn't making Sam feel much better. And there was the burn, the burn that shouldn't have happened and couldn't possibly have been faked...he sighed and dragged a hand, fingers spread, through his hair before rinsing his mouth and pitching his toothbrush into the bathroom's small trash can. He wasted no time in retreating to his bedroom, so he could lie down in the darkness and the warmth and, hopefully, fall asleep. All of the complaints that his tired body had had this morning had come back, and they'd brought friends.
He wasn't going to get around to Elspeth tonight.