Castiel was still glowing from all the power of Purgatory's souls. The creature that stood before Sam and Dean Winchester looked like Castiel. He sounded like Castiel. But he was not Castiel anymore. His stature. His aura. His presence. It was all so terrifyingly powerful and intimidating.
"Cas, please. Don't do this," Dean pleaded, his voice quivering. He needed to fight back the tears and keep his poker face, but Dean already knew that he had lost yet another dear friend. With his eyes to the ground, Dean dropped to his knees, void of what little hope he had left.
"It doesn't have to be like this. Sam. Dean. Join me. Together, we can save the world. Imagine all of the possibilities."
Despite all of the power, Sam could sense a genuine optimism in Castiel's voice and a glimmer of hope in his eyes. But, Dean was still on his knees on the cold, concrete floor, his posture slouched in weakness and defeat. Castiel notices, walks over, and kneels down to come face-to-face with Dean.
Castiel cradles Dean's dirty, bloody face with both hands and lifts his head so that they're looking into each other's eyes. "Come with me, Dean. We can be together and rid the world of all evil. That's what you want, isn't it?" Castiel whispers.
"I wanted that with my friend, Castiel. You're not him. I don't know who you are." Within that moment, a switch flipped in Dean's head and his body, weakened by defeat just minutes before, was now filled fiery rage. He shoved Castiel away with such powerful force that both Sam and Castiel were in disbelief. Dean got himself off the ground and menacingly walked towards Castiel, both fists clenched and ready to throw a punch. But, Castiel knew what was coming and with the flick of his wrist, Dean was thrown into the wall with so much force that his body cracked the concrete.
In his brother's defense, Sam bolted towards Castiel. But, before Sam even made his fourth step, Castiel froze him in his tracks. With a furrow in his brow, Cas looked into Sam's eyes apologetically.
"I really am sorry that things turned out this way."
And with that, Castiel disappeared into thin air.
Regaining control of his body, Sam ran over to his brother. "Dean. Dean!" Sam screamed, grabbing Dean's shirt and shaking him. Dean gasped for air and sprung back into consciousness. "Where is he?! Where'd that son of a bitch go?!" Dean picked himself up off the ground and looked frantically around the dark, empty room. With a pang of disappointment, Sam said, "He's gone. He's just gone." With his eyes wide in disbelief, Dean turned around to face his brother. But that disbelief transformed into pure rage right before Sam's eyes. Dean let out a barbaric yell and punched the concrete wall, leaving a dent. Fuming with anger, Dean clenched both his fists until his knuckles turned white and his breaths were loud and heavy like those of a raging bull.
Sam was terrified of his brother. He just witnessed him punch and dent a concrete wall! Dean's demeanor was so savage and Sam could've sworn Dean was growling. Not just any growl, but a growl with the likeness of a hellhound. Sam grabbed Dean by the shoulders and attempted to shake the rage out of him. With desperation in his voice, Sam yelled, "DEAN! DEAN!" in search of his brother within this body he was grabbing. Then, the eyes of madness soon returned to the protective eyes of Dean Winchester that Sam was accustomed to. Sam pulled Dean into a strong hug, with the relief of having his brother back.
*****
It's been a week since Castiel disappeared and Dean's... moment of darkness. For the past seven days, Dean had been living off of beer and cheap whiskey. He hadn't said much either. Dean mostly just sat at the table, lost in thought, watching his cup as he swirled the whiskey inside.
Sam didn't confront him about that night but he couldn't stop thinking about it. The anger. The growl. The evil in Dean's eyes. He didn't know what it was, but he had an idea. Ever since Dean was rescued from Hell, he didn't seem like Dean. At least not completely. Sam called Bobby to tell him about what happened to Dean the night Castiel disappeared and to ask him if it was possible that Dean might be missing a piece of his soul. It wasn't entirely impossible. Sam experienced a drastic personality change when he returned from hell because his soul was left behind.
"I'm not so sure, Sam, but I'll dig around and see what I can find."
"Thanks, Bobby." Sam pulled into the motel parking lot and turned off Baby's engine. With bacon cheeseburgers in hand, he heads towards the room. But before he unlocked the door, he heard voices inside the room. He pressed his ear against the door. "Crowley?" Sam whispered to himself. He could recognize that annoying, raspy voice anywhere. Instead of barging into the room, Sam stayed outside, ear pressed to the door, eavesdropping to possibly catch some answers to what happened that one night last week.
"Just tell me where Cas is, Crowley!" Sam could hear that growl in Dean's breath again.
"Touchy, touchy. Calm down, Squirrel. You know how I get when you're mad," Crowley teased.
Dean remained silent, but Sam could hear his angry breath through the door.
Crowley let out a big sigh as a sign of defeat. "Alright. Alright. Now I don't know where your little lover boy is, but I heard it through the Hellvine that he still wants you by his side. So I'm betting that if you just say a little prayer, our little Castiel will come flying to you. I swear... you Winchesters just can't leave anything alone, can you?"
Sam had heard enough. So, he swung the door open, but Crowley was already gone.
"I heard voices in here." Sam implied this as a question, giving Dean the opportunity to confess why he was working with Crowley.
"It must've been the radio," Dean answered, pointing to the old contraption on the night stand. "Do I smell a cheeseburger?"
So Dean was hiding secrets from Sam. Again.
"So, I found a case about three towns over, and I thought I'd check it out by myself since you're not... feeling like yourself," proposed Sam. He was preparing to hear Dean's spiel about sticking together and working together on every case. "Yeah, okay, sounds good," Dean mumbled with a cheeseburger in his mouth. "'Yeah, okay, sounds good'?" questioned Sam, "you're fine with me taking on a case... all by myself?" Jokingly, Dean patted Sam's shoulder and responded, "You're a big boy now, Sammy."
*****
There was no case. Sam just needed to get away from Dean so he could find out what was going on. In an empty warehouse, Sam set up everything needed to summon Crowley with an added Devil's Trap. He lit a match, threw it into the bowl, and, almost simultaneously, Crowley appeared in the center of the Devil's Trap Sam spray-painted onto the ground.
"Ah. The other Winchester. Hello, Moose. You and your brother should really ease up on the summonings. The other demons are getting jealous of me."
Sam wanted to punch his smug, little face. "There's no time for jokes. I want to know what you told my brother and what he-"
"What he's planning to do," Crowley sighed, finishing Sam's sentence. Throwing his hands in the air, Crowley answered, "I don't know! We don't sit down for coffee and discuss our plans for the weekend. He just wanted to know where Castiel was."
"And where is he?" Sam implored. Crowley sighed. "Where is he?!" Sam angrily yelled in desperate need for answers.
"I. Don't. Know." Crowley's patience was running thin. "Geez. You and your brother have such bad tempers. I mean, at least your brother's a demon. What's your excuse?"
"Wait. WHAT." Sam was in disbelief. Dean's a... demon?
"Oh. Squirrel didn't tell you? Oops. Maybe I was supposed to keep that a secret."
In shock, Sam turned around and started running.
"Moose! Come back and let me out of here!"
Sam didn't look back. He knew Crowley would find some way to get out of the trap. Sticking the key in the ignition, the Impala roared to life, and Sam sped away, heading back towards the motel.
*****
"Castiel. I need you. Come back. You were right. We need to be together."
Dean wasn't sure if praying would lure Castiel, but it was worth a shot.
There was no response. Then, Dean knelt beside the motel bed with his elbows digging into the mattress, hands clasped together, and eyes closed shut.
"Cas. Please. Come back."
Dean's eyes shot open to the sound of fluttering wings. He whipped his head behind him and there he was. Cas still wore his signature suit and trench coat, but within a week, it seemed as if he had aged five years. He seemed so tired. The exhaustion was written in his eyes.
"Dean. I heard your prayer. And I'm here now."
Dean bolted up and pulled Castiel into a long embrace. Then, Dean grabbed Castiel's face between his hands as Cas did to him that night last week. They stared into each other's eyes as if they were forgiving each other for anything and everything they've ever done. Dean inched his face closer to Castiel's and, with a sharp inhale, kissed Castiel.
Castiel wrapped his arms around Dean's waist and pulled him closer until their hips were pressed against each other. Dean kept his hands clasped onto Castiel's face, guiding him in their passionate haze. Their breaths intensified and their bodies began to synchronize with one another. Dean reached for Castiel's trench coat and pushed it off his shoulders and onto the floor. Turning him around, Dean pushed him onto the bed and straddled him.
"This is what I want." Dean threw his jacket on the ground and bent down to kiss Castiel again. They were in their own little world. Just the two of them. Together.
Castiel began to unbuckle Dean's belt when he felt a sharp sting on his lip. He pulled away from Dean's lips and tasted blood in his mouth. He brought his finger to his lip and there was blood.
"Did you just bite me?" implored Castiel, confusion written upon his eyes and furrowed brow.
"If that hurt," Dean smirked and reached for something in his back pocket, "then this might be a little more painful."
Dean's eyes turned black.
At that moment, Sam bust down the door. But he was too late. Sam witnessed Dean thrust the angel blade straight into Castiel's chest right before he had to shield his eyes from the bright, white light that filled the room.
Once the light was gone, Sam rushed into the room to pull Dean off of Castiel.
Dean's eyes were human again, but those eyes saw what had happened to Castiel. With his the black imprint of his wings on the ground, Castiel was dead. And Dean realized he was the one who had done it. He dropped the Angel Blade on to the floor and dropped to his knees.
"Dean, this - this is not your fault. There's a demon inside you."
"No, Sammy. I am the demon." Dean stares into his little brother's eyes, and Sam looks back, as a single tear rolls down Dean's cheek.
Dean grabs the angel blade and places it in Sam's hand.
"You gotta do it, Sammy. You gotta do this. For me. I can't live like this." Dean tried to keep his voice from shaking, but it was impossible as tears began to stream down.
"No, Dean. We can figure this out. We always do." Sam tried to muster as much hope and optimism as he could. "You can't leave me, Dean. I need you."
"Sammy, there's no way out of this one. You have to do this. Just promise me one thing." Dean lovingly placed his hand against Sam's cheek. "Promise me you'll find a girl, marry her, have kids, and live in a house with a white picket fence. Promise me you'll live a normal life."
Sam couldn't find the strength to use his voice, so he just nodded as tears filled his eyes.
"Sammy, I lo-." Then the black eyes returned and Dean yelled with that primitive growl.
Sam knew what he had to do. He took one last look at what remained of his brother and thrust the angel blade into Dean's heart.
And, just like that, Sam Winchester sat alone in a motel room with the corpses of two people that he loved.