Dean was woken up by the sound of yelling and the shaking of his arm. The yelling was muffled and the shaking caused a thumping to sound in his ears. After a few minutes of this, the voices began to become clear as the thumping faded into the nothing, Dean opening his eyes to find Castiel and Sam standing above him.

Castiel offered his hand to Dean as Dean grasped it tight in his and pulled himself onto his feet. The world around him spun for a moment as he tried to pull himself together. As he did, Sam's hands were on his hips with a shaking head.

"What happened?" Sam asked.

"I came out here to…" Dean muttered, his eyes going wide. "Carly."

"Yeah, she's...gone." Castiel said as Dean met his gaze. "When I returned, I noticed neither you nor Carly were in the room. I woke up Sam and we came out here to find you lying unconscious."

"I don't get it. Why would she just run off like that and knock me unconscious no less?" Dean asked, rubbing his forehead.

"This may explain a thing or two." Castiel said, lifting up an envelope. "I found this on the table in the motel room."

Dean pulled the envelope from Castiel's hand, noticing his name upon its surface. He ripped it open to find a piece of paper inside. He flipped it open to reveal a note, which he read aloud to the others.

Dear Dean,

I'm sorry that I couldn't say goodbye in person, but I hope this makes up for it, if only a little. I am giving myself over to Lucifer so he can possess me. Doing so saves Sam from taking on that burden and you from having to lose your brother. Now that you have the key to the cage, you can stop Lucifer and end this.

Don't hesitate because he is wearing my skin...please. This is bigger than all of us and I am willing to die to save you...all of you. I hope you can forgive me. Save the world, I know you can. I love you Dean and I'm sorry we couldn't have more time.

From,

Carly

When Dean finished reading the note, he crumpled it up into a little ball and slammed his fist into the car behind him. Sam and Castiel looked at one another with confusion as they had questions.

"Why would Carly give herself up to Lucifer...to save me from that burden? What is she talking about, Dean?" Sam asked.

Dean looked at his feet before meeting Sam's gaze. "When Zachariah captured us he told Carly and I that in order for Lucifer to be sent back to hell he has to be possessing his true vessel, which means either you or Carly would have to go with Lucifer into the cage when we opened it."

"And you just decided to not tell me that?!" Sam yelled.

"I was going to!" Dean yelled back, his knuckles turning white. "I just wanted us to come up with a plan first and then I was going to try to find another way. If that didn't work, I was going to tell you."

"You should've told me right after you found out! You don't just hide something like that from someone, Dean!" Sam snapped.

The two began to approach one another, anger flaring in their eyes and chests raised. Castiel realized this was the sign of a fight ready to begin, so he stood between the two. He placed a hand on each of their chests to get them to stop.

"Fighting is not going to solve anything. Our goal right now should be to find Carly and bring her back. After we do that, we can figure out what to do next," Castiel suggested.

"She could be anywhere by now," Sam groaned.

Dean looked down at his feet as he ran a hand through his hair. He closed his eyes and when he reopened them he found a piece of paper wedged under the tire of the car beside him. He bent down and picked up the paper to find an address written on it.

"I think I know where she's headed," Dean said, showing the paper to Sam and Castiel.

"That could be from anyone," Sam pointed out.

"I have a gut feeling and my gut feelings are never wrong." Dean said, turning to Castiel. "Can you fly us to this address?"

"If Lucifer is inside, he may be waiting for us. He probably has every spell locked and loaded to keep us out," Castiel said.

"I don't care. Can you get us there?" Dean repeated.

"Yes, I can get you there.

"Are you sure this is a good idea?" Sam asked.

"That's all we have. If we don't try, Carly will be possessed by the devil himself and I won't let that happen, not if I can help it. Now are you coming with me or staying here?" Dean said.

"I'm coming along," Sam muttered.

"Then let's go, shall we?"

Dean looked at Castiel who was just as nervous as Sam was. This was a horrible idea, but for Carly they were going to risk it. Castiel placed a hand on both their shoulders before disappearing into the late night sky.

Carly parked the car on the side of the road, getting out to look up at the abandoned apartment building in front of her. It barely looked safe enough to stay standing, but she had no choice but to go inside. With a sigh, she shoved her phone into her pocket and headed through the shattered glass door.

As she walked further into the building, she found an elevator, but it was hanging by a single wire. So, she headed for the staircase on the other end of the lobby. After three sets of stairs and one corridor later, she found herself in front of the apartment number Lucifer had given her.

She stood there for several moments, trying to pull herself together. When she went to grab the knob, the door slowly swung open in response. Carly squeezed her hand tight before taking a deep breath and walking into the room.

It was identical to the one in her dream and made her just as uneasy. As she took a step forward, the floorboards creaked underneath her. Carly stepped into the other room and found Lucifer in the same spot as he had been in the dream, looking out the frost-covered window.

When Carly stopped in place, Lucifer turned around to face her. His vessel looked as it had in her dreams, except there were burns across his forehead and hands. He was burning up the meat suit from the inside out and soon the body would be nothing but ash, whoever was in there with him was either dead or would be soon.

Lucifer cleared his throat. "Death told me of your early arrival. I'm glad you've made the right decision."

"If I do this, you promise my friends will be left alone?" Carly asked.

"Yes, safe and sound. I promise."

Carly looked down at her feet and as her gaze rose to his and her mouth opened to speak, loud footsteps could be heard coming toward the room. Lucifer's hand rose and twisted to close the main door to the apartment, fists slamming against its surface moments later. Muffled yelling could be heard, Lucifer and Carly realizing who it had to be.

"Looks like your friends have come to interrupt," Lucifer said, looking from the door to Carly. "I thought I told you to come alone."

"I did but they must've figured out where I'd go," Carly said, looking back at the ruckus behind the door.

"I can only hold the door for so long. What is it going to be, Carly?" Lucifer said.

Carly looked from the door back toward Lucifer. She gritted her teeth as she sighed in defeat. "You'll let them live, right?"

"Yes, they will live. All you have to do is say yes."

Sam, Dean, and Castiel were banging their fists upon the creaking door. Castiel tried to fly the group in, but whatever Lucifer was doing, kept him at bay. The three continued to yell and bang their fists until the door clicked.

They looked at one another with confusion as Dean wrapped his hand around the doorknob, twisting to find it unlocked. He pushed the door open as it slammed back into the wall behind it. The three readied their weapons and slowly walked into the dust-covered room.

They made their way further into the apartment when they found Carly standing alone in the center of what was once the living room. Her back was to them as she looked down at her feet. The three kept on guard as they slowly got closer.

Sam and Castiel hung back as Dean took the lead. He came to stand right behind Carly as he placed a hand on her shoulder. "Carly, are you okay?"

Carly's back stayed facing the three as she slowly raised her head, eyes opening with a dark grin. She turned around with that same grin, muttering under her breath. "Carly can't come to the phone right now."

Dean's eyes went wide. "Lucifer."

"Bingo."

Lucifer's hand rose, flinging it forward as Castiel and Sam hit the opposite wall going unconscious instantly. As they hit the floor, Carly wrapped her hand around Dean's throat and slammed his back into the wall beside her, lifting him into the air so his feet couldn't touch the ground.

"I thought it would be a lot harder to get her to say yes to me, but I'm glad I was wrong," Carly said, her eyes glowing a bright red.

"Get...out...of...her," Dean gasped, struggling against her grasp.

"No, I don't think I will. She willingly said yes to me and I have no intention of leaving," she explained.

"So, are you going to kill us now that you have what you want?" Dean asked.

"No, I made Carly a promise that I'd let you all live. Normally, I'd break that deal faster than it would take to blink, but I'm feeling generous today."

"You're a monster," Dean gasped.

She huffed in amusement. "Oh, I've heard much worse than that, Dean Winchester. But you don't have to be afraid of me. What do you think I'm going to do?"

"I don't know. Maybe deep-fry the planet?"

Carly raised a brow. "Why? Why would I want to destroy this stunning thing... beautiful in a trillion different ways. The last perfect handiwork of God? I do not want to destroy this planet, I just want revenge on those who have wronged me. Once I kill Michael, I will leave this planet be. Now I must be going and I suggest you do not follow as I can only be so kind."

With that, her grip loosened and Dean collapsed onto the floor in a coughing fit. As he hit the floor, she took a step back and made her way toward the fire escape. After one step, Dean gruffly yelled after her.

"I will never say yes to Michael!" Dean yelled.

Carly laughed before turning to face him. "Who ever said he was going to possess you?"

Dean looked at her with confusion as she vanished out of sight. Dean pulled himself to his feet and stumbled to the fire escape, but found no sign of her. A pit was growing in his stomach and he knew things were just going to get worse from here.