Author's Note- The unexplained time laspe near the end of Skin has always bothered me. If the shape shifter simply dragged Sam from the couch to the pool table, why wouldn't it be shown? Something had to have traspired in that time, and this is my take on it.
"What are you gonna do to me?"
"I'm not gonna do anything. Dean will, though."
Sam shook his head in denial, ignoring the soft clink of stainless steel utensils behind him. "They'll never catch him."
"Oh, it doesn't matter. Murder in the first, of his own brother. He'll be hunted for the rest of his life."
Sam's heart quickened as he heard unmistakable sound of a knife being pulled from its sheath. He had been stupid coming here by himself. He shouldn't have let his guard down. Always expect the unexpected, isn't that was Dad had drilled into his head for 22 years? And now look at him. Bested by a shape shifter.
A drop of warm blood ran down the back of his neck. "Where's Dean?" he asked, his voice not betraying how frightened he really was.
"I wouldn't worry about him right now," the shape shifter replied, setting the knife on the counter with a heavy, purposeful clank. "It's your life that's on the line right now."
Sam tested his bonds, welcoming the burn in his muscles. They were secure. "You don't know where he is, do you?" He was testing the waters, searching for weaknesses. Always hope for the best.
A hand fisted in his hair, painfully close to the wounds on his scalp, and Sam was suddenly staring at the ceiling. "I said, keep your mouth shut," Dean's voice hissed in his ear.
Sam caught himself as he was pushed roughly, shifting his weight in order to straighten against the couch once more.
The shape shifter moved in front of him, standing awkwardly close. "Very good," he said, mistaking Sam's silence for obedience. "You're a fast learner."
Another drop of blood tickled its way down Sam's vertebrae. His head was throbbing; there was probably shards of glass imbedded in his skin. Sam clenched his jaw as he forced himself to look up at the shape shifter. "Why do you do it? Do you get some sort of power trip from killing innocent women?"
Dean's face grinned down at him sadistically. "Don't kid yourself Sammy. I'm gonna kill you too."
"Go to Hell."
"Oh, I plan on it."
Dean's fist crashed into his cheekbone with enough force to send Sam to the floor with tears in his eyes. His face was numb and hot the inside of his mouth was bleeding. He lay there, unable to rise between the disorientation and the rope around his hands.
"You guys really have one messed up family, you know that?" the shape shifter taunted, sinking to his haunches next to Sam's face. "It almost makes mine look like the Partridge Family."
"You're a coward."
The shape shifter smiled in Dean's signature cocky way. "You never could keep your mouth shut, could you Sammy?" He rose suddenly and punctuated the nickname with a violent kick to Sam's midsection.
Pain exploded in his belly and Sam curled in on himself, reflexively trying to wrap his arms around himself for protection. He pressed his uninjured cheek into the itchy carpet fibers as he gasped for breath.
The shape shifter continued, unconcerned. "Always stirring things up between Dad and Dean, always pitting them against each other. Dad wanted you to be excited about hunting, he wanted you to want it… but Dean… Dean always stood up for you, didn't he? Always took your side- and ultimately, the brunt of Dad's wrath."
Sam shook his head weakly against the perfumed carpet. He opened his mouth to argue, still trying to regulate his breathing, when Dean's fist curled in his hair once more. He was forced to look into Dean's cold green eyes.
"You're such an ungrateful little brat," Dean's voice hissed as Sam was yanked off the floor. "Do you know what kind of sacrifices Dean made for you? Do you?" he punctuated the question with a viscous shake that left Sam nauseous. "I raised your puny ass! I fed you and changed you and gave you fucking baths… and what thanks do I get? You abandon me for some ridiculous dream that you might make it at Stanford!"
The hand on his head disappeared and was replaced by a blow to the jaw. Once again, Sam found himself on the floor and staring at the leg of the coffee table before him. The change in narratives was not lost on Sam and he felt anger brewing inside him, even through his pain. "You're not my brother."
"Of course I am. How else would I know all of this priceless family history? You just don't want to finally see what's been going on all this time."
The accusations hurt worse than the blows. Sam tried to tell himself the thing was wrong- it didn't have all the facts, all the history. It had only downloaded parts of Dean's memory, not the whole picture. He'd never meant to hurt anyone by going to college. He'd only wanted a better future for himself. He wanted the days of hunting to be nothing more than funny stories he'd tell his grandchildren. He'd never meant to betray Dean…
"You're quiet all of a sudden," the shape shifter taunted. "Cat got your tongue?"
"You're wrong," Sam said. "Dean doesn't feel that way." He needed to say it out loud.
The shape shifter only smiled. "You ask him one day. Oh, that's right-" The smile turned into a snarl and lightning fast, it landed another blow to Sam's face. "You won't be alive."
Spots danced in front of Sam's eyes and he swallowed the taste of blood as bile crept up his throat. Then, before he could compose himself, he was being dragged across the floor by his clothing.
"Dad was always harder on me, especially after you left." Dean's shoes squeaked as they scuffed the kitchen tile. "I didn't mind though, at least I gave him one good son. I was always the favorite."
Guilt was slipping in through Sam's weakened defenses. The floor continued pulling at his clothes as the ceiling passed by overhead. The shape shifter grunted and Sam took pleasure in knowing that even semi-conscious, he was still being a pain in the ass.
"You're not him," Sam insisted once more. Suddenly, he stopped moving and was dropped upon the floor next to the pool table.
His denial earned him a kick to the ribs. "I am whoever I want to be!" the shape shifter growled, watching as Sam fought to pull air into his lungs.
Sam could only gasp as the pain ignited his side. A tear slipped from the outer corner of his eye and burned a hot trail to the carpet below.
At last, the shape shifter moved away. "You'd think after all those times of saving your ass, Dean would have taught you some manners," it grumbled, heading into the kitchen.
Sam rolled onto his back and concentrated on catching his breath. He took pride in the fact that the shape shifter was no longer referring to Dean in the first person. Out of his whole situation, imagining that monster as his brother was the most unsettling.
Glass clinked and the sound of running liquid ensued. "I must say, I will be sorry to lose this skin. Your brother's got a lot of good qualities. You should appreciate him more than you do."