Author's Note: Unbeta'd. All mistakes are my own.
AU where Dean spends 40 more years in Hell, as the angels are unable to find him.
For the majority of the fic, Dean is known as 'Cain' (as in Cain and Abel) because I felt uncomfortable writing about Dean torturing Sam, while as Dean himself, and I don't really believe that it was Dean during his period in Hell, because 30 years of torture and then another 10 torturing can change a person completely.

For Cain, life (or rather death) was the greatest it had ever been. He couldn't remember his life before he entered Hell, and the thirty years that he resisted the good for was still a blur.
However, Alastair and Meg had told him of his younger brother who continued to screw up, and Dean ended up being tortured because his brother was stupid enough to die. He had been told about how his morbid life was miserable, and full of pain, until he finally gave in and joined the right side. He'd been Dean Winchester, murderer of the good and alcoholic man-whore. Now he was Cain, a skilled torturer under Alastair, and he loved every minute of it.
He spent the beginning of the day in his chamber, curled around Alastair, until they were sent the first soul of the day. Alastair showed him how to make them scream, and rip them apart, only to put them back together again. Cain was good at this, and hell, he enjoyed it. The bloodcurdling screams sent shivers down his spine, and he grinned as they begged him to stop, which would make him only torture them more.
However, this day was different. When Cain awoke, Alastair was missing. He wasn't at the racks, so Cain presumed he was commanding other demons, until Alastair entered their chambers, grinning maniacally. "Cain!" he yelled, pulling him into a rough kiss, "I've got a surprise for you." Cain stared, suspiciously, "What might it be?"
"Come," Alastair guided Cain over to the racks, and showed him the soul attached to it.
There was nothing unusual about it, other than its height, which Cain saw only as more skin to rip of it, and more blood to soak out of its veins. It was a man, bloodied and bruised, and wearing an amulet over his shirt. Cain absentmindedly clutched his own amulet, and stared at the soul's understanding that they were exactly the same. He shrugged, the amulets must be mass-produced, or perhaps they had been members of the same religion.
Yet he couldn't shake a feeling of familiarity and love, and he hated himself for being so sentimental, and human, which was the very thing that kept him from the right side.
The soul yelled out something Cain couldn't understand, as he stared at him. Alastair whispered, "See this wreck of a man? This is your brother, the one that made you get tortured, here on the rack for you to torture." Cain gazed at Alastair, and then at the soul, in disbelief. Abel, in Hell? No, Abel was loved by God, the favourite, yet it seemed fit, as he was both evil and manipulative.
He understood what the soul was yelling out, in a continuous pattern, desperate and afraid. Cain's lips curled, as he picked up a knife, and Alastair smiled, "I knew you'd like him. Torture away, lover, show me all that you have learned," and stood back, to watch Cain face the soul, whose expression was full of hope. "Dean," it called out, "I'm sorry! Dean! It's me!" Dean laughed, remembering all that Alastair and Meg had told him, and shook his head. "Brother," he said simply, trying it on his tongue. It felt weird, as he hadn't called anybody that in over sixty years. Alastair had told him that he had always screamed out for his brother for the first twenty years, and that he was keeping him from joining the good side, and the right side.
The soul rattled the chains, thinking that his brother had recognised him. Cain drew the knife down his brother's shirt, and ripped it off him. He stared at the chest, which was rising and falling rapidly, despite the soul being dead. He smirked; thinking of how he would rip out his lungs, alveoli by alveoli, and then his windpipe, and imagined how his brother would gasp for breath, eventually dying at the hands of his brother, and justice would be served.
He led the knife in a wavy pattern across his brother's waist, and tormented, "Alastair told me about you, brother. Abel, the younger brother, loved by Cain, despite being sinful and sly." He sliced the knife into his brother's ribs, and his brother cried out in pain. Cain froze on hearing his brother's screams, but shook it off for the love that was once there, so many years ago. This was what he had waited for for so many years; to torture his brother like his brother had tortured him. "I've waited so many years for this, brother," he said, mockingly, "To be able to torture you all day, and all night." Alastair, whose presence Cain had forgotten, put his arms around Cain's waist, pulling him towards him, tightly. He beamed, "I see you're enjoying your present. I love seeing you all angry and vengeful, lover. Makes me hard, seeing you like that." Cain kissed him, greedily licking the insides of his mouth, before returning to the rack. Alastair moaned in disappointment, but stopped once Cain began cutting deep into his brother's skin again. His brother shook his head, "It's okay, Dean. It's enough to see you. I've missed you so much, and I know it's not you." Cain halted, and dug the knife in deeper. "Quiet," he snapped, "I am your brother, and I am going to kill you continuously, forever."He slammed his fist onto the tools trolley in frustration, leaving a fist mark in the hard metal, a side effect of his new-found power.
A voice sniggered from behind him, "Well, someone's having a bad day at the office." Cain turned, to see a smartly dressed middle-aged man smiling next to Alastair, smugly. Cain barked, recognising the man as Lilith's second-in-command, "What do you want?" The man gestured to Alastair, and then to the door opposite to the one leading to Alastair and Cain's chamber. The door led into the Centre Courtyard, where the highest of Hell's demons were usually found. Alastair, being the Grand Torturer, was one of these few.
"Lilith requests Alastair presence. So if you don't mind torturing that soul, seeing as it's your job, I'd like to escort Alastair to Lilith," the demon flashed a grin at Cain, and then turned to Alastair, "Shall we?" Alastair nodded, glancing at Cain, and his brother, who was still on the racks, "Don't wait for me. Do whatever you'd like, and then you can show me what you've done later," he grinned ferociously, and added, "Lead the way, Crowley." Crowley looked at the soul on the rack, and screwed up his nose in disgust, "Well, have fun torturing Moose, Squirrel," and exited the room, followed shortly by Alastair. Cain waited until the footsteps grew faint, along the old-fashioned corridors, and then asked his brother, "What did you do to arrive here?" His brother, known to the others as Abel, sighed, remembering his regrettable actions. Cain stared, watching every single one of his moments, whether they were blinks or twitches, trying to tell what he could from the man. Alastair had told him how to read under the mask of men, to see what type of torture pained them more. He appeared more in pain now than he was when Cain was cutting him, and he made a mental note of it. Abel finally said, "There was a fight. I was drunk and grieving, and convinced that the man at the bar was possessed by a demon. I wanted to kill every single one of those sons of bitches, for you Dean, but I was seeing demons everywhere, and when I stabbed him... nothing happened. No weird flashes or eyes turning black, he just died. I knew immediately, what I had done, and I ran..."

The barman yelled, in pain and everything stopped. Another man reached out to grab his arm, yelling coarsely, and he stared at the motionless body next to him. The other man threw a punch, and he heard his nose snap. He pushed him away, and stormed out of the bar, before he could consider what he'd just done. He was being followed, he knew, but he didn't care. He'd just killed a man. A man with a life, and a family, and perhaps a lover waiting for him at home. He'd ruined that man's family's life, because he didn't check properly. His own yearn to kill hell beasts, and his own arrogance had caused the life of a human being. He stumbled into an alley, and crouched down, head in his hands. He heard footsteps in front of him, and a ridicule voice laughed, "Well, well, well. Look what we have here," Sam knew that he'd probably get beaten into a pulp. He deserved it, for killing a man, and looked up, seeing who the voice belonged to. It was a woman, who looked to be in her mid-twenties, but her eyes glowed black, as she smirked, "Nice to finally meet you, Sammy. I've heard so much about you." Sam sighed, acknowledging how ironic it was that a demon would be the one to kill him. If that was to happen, anyway. Nobody had told him why Lilith had been unable to kill him when Dean had gone to Hell.
Dean was still in Hell.
That was his one regret: that Dean had gone to Hell. He was getting tortured for eternity, only for Sam to be tortured as well.
The demon grinned, "Aren't you gonna say hello, Sammy. Didn't your mommy ever teach you any good manners? Oh wait..." she smiled smugly, and Sam grunted, "Just kill me, okay?" The demon stuck out her bottom lip, jeering at him, "Aww. Is wittle Sammy uwpset?" she pulled a knife out of her jacket, "But don't worry. It'll be over soon. You've already earned an eternity or two of torture," she leered, stroking his face with the knife, cutting his cheeks slightly, "I might give them a hand when you're down there. So, buried or cremated?" Sam fumed, tempting taking the knife from her, but she sneered, "Fine, Sammy. I'll end it for you. Oh, and before you go, say hi to your brother for me. I hear he's one of the best torturers Hell has to offer, but I guess you'll find out. Oh, and he's taking it up the ass, too." Sam shook his head, annoyed at the demon for feeling the need to add a quip or two, just like every other demon he'd faced. Must have been a demon-ego thing. Well, he was sure to find out.
The knife plunged into his brain, and he felt his body shut down.

Cain wanted to congratulate Abel on what a great actor he was, but there was something in him that told him he was telling the truth. Disappointment, maybe, mixed with a whole load of it's not your fault, Sammy which didn't make sense to Cain at all. He knew that his brother was manipulating him, using his petty sentimental feelings against him. He picked up his knife, and sliced another cut into Abel's chest. "Did I ever tell you that you're a great actor? I want to truth, not some cliché, 'oh poor me' sob story." Abel shook his head, and closed his eyes, wincing slightly at the cut, though he had suffered much worse. "It's the truth, Dean. I know you're in there, somewhere, and you believe me." Cain stabbed into Abel's stomach, angrily, and watched as the blood oozed out, hoping it would brighten his mood. Instead, it only made it worse. The sentimental Cain, the one with the weak feelings of love and hope, hidden away deep inside the dominant Cain was returning, slowly, and Cain struggled to keep him at bay. He retreated, turning away from his brother, and the real Cain, the human Dean Winchester, took control (albeit for only a few seconds) opening his mouth, stammering, "Sammy?"
Sam's face lightened immediately, as he yelled, "Dean!" Cain regained control and plunged the knife back into Sam's stomach. Sam yelped, but lost no hope, to Cain's dissatisfaction, by saying, "Dean! It's okay! I'm here!" Cain pierced the knife into Abel's throat, silencing him, as he twisted it into his vocal chords. "Quiet," he bellowed, "I am Cain, and you are Abel!" he repetitively plunged the knife into Abel's body, continuing even when Abel was still. "I am Cain, and you are Abel!" he echoed, throwing the knife across the room. He shook as he covered his hands, echoing his words, curling up into a ball, on the cold, hard, concrete floor, still as the body on the racks next to him.