"Put the gun down, Sammy!" Dean shouted outside on the sandy parking lot of their motel room.

"Who the hell are you?!" Sam demanded, pulling the trigger back just to show the figure in front of him the amount of his sincerity.

"Dude! It's me….your big brother! What the hell's gotten into you?!" Dean's voice was shaky, his face bathed in a reddish hue from the neon 'Vacancy' sign above the brothers' heads.

Sam narrowed his eyes. He knew something was wrong the minute that Dean refused to eat earlier. He couldn't remember the last time Dean turned down a slice of pie, but it wasn't the food that set him off. It was a combination of strange occurrences for the past several weeks, all culminating with Dean's "slip-up" after the pie incident that had brought Sam's theories to reality. Dean didn't think Sam had noticed, but he did.

And it sent shivers through Sam's body.

As Dean was leaving the motel room a short while ago to pick up ice, Sam caught the nightmare in Dean's reflection in the window. It was just a glimpse, a peak, a split second. But it was there.

The darkness. The blackened eyes. The conniving grin.

Without hesitation, Sam had instinctively picked up the closest weapon near him and shoved his brother outside, the surprising blow knocking the older Winchester to the floor while Sam shouted at him to "Freeze!" And now he stood, facing off his brother, uncertain of who would make the next step. Sam knew he had to tread lightly because he had gone into this without any plan of action.

"Tell me who you are!" Sam's voice deepened to a level that would automatically demand respect from most people. But Dean stood with his hands up, continuing to look confused. "I don't know how you managed to get into my brother, but I swear to God, if Dean's hurt…" Sam's knuckle whitened as he put more pressure on the trigger.

He had no intention of shooting the figure that looked like his brother, but he really had no other plan of intimidation. For now, this was all he could do.

"Sammy! Just put the gun down. I'm not a monster. Splash holy water on me if you're not sure."

Sam's eyes darted to the Impala that was parked about 20 feet away from them. He considered it carefully and knew that if he kept his eye on Dean, he could probably grab their water reserves without him getting away.

"Fine," Sam agreed, a flash of uncertainty across if face. He backed up slowly, gun still aimed high, his eyes locked on Dean.

"Look, Sam, I don't know what dreamroot you've been smoking, but can you drop this already? I'm not playing," Dean said calmly, arms still in the air.

"Yeah, I'm not either," Sam mumbled under his breath, not sure if bantering with this 'thing' was a good idea. He approached the car behind him, taking careful steps backwards since he couldn't see where he was going.

"Yeah, this is great. Really cutting into my quality magic fingers time," Dean remarked.

Okay, that sounded like Dean, Sam thought.

"And Sam, while you're over there, grab me Dad's journal from the trunk. I think there might be an entry on brothers who go ape-shit crazy on each other!"

Now, again, this person was sounding more and more like Dean, Sam continued to reason. Maybe he was just going crazy.

Sam still had his aim firmly locked on Dean by the time he reached the car's side door. He opened it up and fumbled within, trying to feel out the canisters of holy water that he knew were kept somewhere in the backseat while maintaining Dean in his sights.

"Hey, now be careful over there. I got me a new issue of B.A.B's and I don't want your filthy mitts all over my ladies before I get to 'em," Dean smirked.

Even under the tension, Sam smiled just a little. His muscles relaxed, ever so slightly, but Sam was beginning to think that Dean was right. This was stupid.

Still, he thought as his hand felt the cool metal of the silver flask, better safe than sorry.

With one swift motion, Sam lifted the flask, unscrewed the cap, and still handling the gun to show Dean that he was in control, he carefully approached his older brother and splashed.

No smoke.

Sam splashed him one more time in the face for good measure.

Nope, nothing.

Dean licked the water from his lips, and forced himself into a closed-mouth smile. "Satisfied?"

Sam sighed with relief. Maybe he was just seeing things. The days were long, the nights short, and sometimes his dreams blended into the sticky, ensnaring web of reality.

Sam hunched his shoulders, taking a pose of exhaustion and defeat, his height nearly the same as Dean's now.

Dean gave a reassuring squeeze of his little brother's neck.

"Hey, man, it happens," and with Dean made a military style turn and proceeded back in the direction of their motel room. "I gotta get that ice still, but all this action got me thirsty for a beer." Dean continued to walk away from Sam while talking, his little brother following slowly behind him. "Oh and dude, I'm sure I can pick up some apple juice from the vending machine for your pansy ass."

Sam smiled, glad to know that his brother was still here with him.

"Jerk," Sam retorted, not letting Dean forget their childhood mantra.

"Idiot," Dean called back to the giant behind him.

Suddenly, Dean couldn't hear Sam's footsteps crunch against the sand anymore.

And he heard the gun, cocked and ready.

"You're not my brother," Sam gritted through clenched teeth, gun aimed firmly at the back of Dean's head.

"Oh sh—" Dean whispered. As Dean turned around, Sam's face turned to one of horror as he was met with the fully grey eyes of his worst nightmare. "You just had to go and do that now, didn't ya, Sammy?"

In the blink of an eye, the gun flew from Sam's grip and slammed into the Impala's windshield 20 feet away.

Holy shit, this guy's strong. How the hell did he get into Dean's body? They were protected! What kind of powerful demon's not affected by holy water? The questions flew quickly throughout his head, but before he could even think them through, Sam felt his body thrown against a nearby tree.

"What a shame! My cover's been blown!" the figure that inhabited Dean's body chided.

Without even thinking, Sam peeled his body off of the tree's rough bark, staggering up to position himself directly in full sight of his possessed brother.

Taking just two short breaths, Sam straightened his body and shot his hand out in front of him. He planted his left leg behind him, cementing his stance. He prepared his mind for the mental onslaught to come.

This was going to hurt like a bitch.

As he closed his eyes, Sam immediately summoned the energy that seemed to rise up and into him from the dirt itself. He could wrap it around his hand and use its spider-like tendrils of electricity to bind with the demonic presence in front of him. All he had to do was aim correctly and hope to God that it didn't kill him.

"Oh how cute! That won't work, S—" the demon began, but that was all it could say.

Cocky sons of bitches. The lot of them.

As the electricity coursed through him, and he awaited the pain that would eventually explode behind his eyes, Sam fought to keep the powerful demon in place. Grabbing hold of the demon spirit was one thing, but keeping it from fighting back with its own psychic arsenal was another.

Sam focused on what Ruby had taught him while he saw Dean's mouth fall open. His grey eyes rolled back in his head, and his brother went into a kind of seizure. Like a scene from the exorcist, Dean screamed as his body lurched and fought the sickness inside of him. The black smoke that came out of his mouth had the high pitched scream of dying animals and the hounds of hell all in one.

Sam would never get used to that sound.

And in an instant, it was all over. Out of habit, Sam wiped under his nose, but didn't think anything of it when his hand came back clean. No blood.

Instead, he just wiped his hand on his shirt as he'd been accustomed to doing, and ran over to his brother's side.

"Dean! Wake up! You were possessed!"

Dean's vision slowly came back to him as he coughed and tried to make another poignant life altering comment.

Disoriented, all Dean could muster was "YOU…wake up…" and with that he fell right back to sleep.

Sam took a quick survey of his surroundings, affirmed that no civilians had seen, and hoisted the older hunter onto his back, determined and happy to get his brother – his real brother – back to the motel room. Tonight had been enough adventure for them both, and right now, all Sam could think about was getting some rest, and later researching the demonic foe he'd just battled. He had to figure out exactly how something like that could've slipped under his radar unnoticed.

How did it get through Dean's protective sigil etched on his skin?

And most importantly, how could something so strong be defeated so easily? While Sam washed his face under the cool water, he froze as he finally realized what had been disturbing him so much about his latest encounter.

Where was the headache?

Sam gripped the sides of the mirror above the bathroom sink and raised his chin up.

Where was his nosebleed?

It was at that point that Sam stared himself down in the mirror and realized for the first time that he actually felt good. No, better than good.

He felt energized. As he watched himself in the mirror, taking a deep breath, his muscles shuddered as if coming out of a deep massage.

It felt so damn good.

He turned around and eyed Dean sleeping soundly on the bed completely on his stomach, face down into a pillow, and still managing to breathe. The thought that his brother was safe calmed his nerves, but only a little.

For he remembered what Ruby had told him. Things will get easier, the farther along you get. The more you practice.

But something about the mind-splitting headaches, the churning stomach, and the bitter bile that arose in his throat that came along with these exorcisms had eased his conscience. The pains had gripped him, planted him in the hope that he was still human, and what he was doing…well, his body would try to fight off because it was not truly a part of him. This demon part, this blood, it would never be him.

But after tonight, however, it was too easy, too natural. It came like breathing.

Sitting aside Dean's bed, Sam inhaled and gripped his head in his hands, still feeling the energy boost inside his body.

Outside, he didn't need to blink.

"Oh shit, Dean," he said to the motionless body in front of him.

Outside with that demon, he hadn't even needed to think.