So I was on Tumblr forever ago and I came upon a post that said something along the lines of, what if Lucifer dropped hints about who he was really was to Sam by saying things Hallucifer had said. I thought, 'That sounds pretty interesting, I wonder if it's already been done.' It's practically been eating at me for these past weeks so I decided to put it to paper, hope you enjoy.

Disclaimer: I don't own Supernatural or anything related to it.

Sam knew there was something up with Castiel. He was acting weird . . . er. He didn't know the Angel as well as Dean but he was certain he was acting different. He'd at first attributed it to seeing his brother in the cage but it had been going on for days afterward. There were also times when his voice stopped sounding like he'd just swallowed a glass of nails. Whenever it happened, the Angel would give his head a little shake and go back to speaking like he usually did.

Not to mention that every once and awhile he would purposefully start talking regularly and say things to Sam like they were sharing an inside joke. It always made Sam feel uncomfortable because as far as he knew they didn't have any. The thing is, they always sounded familiar, like he'd heard them somewhere before.

He didn't have anything to do at the moment so he decided to mull over all those times.

Both Sam and Dean had been surprised when Cas had declined their offer for him to go with them. They'd both shrugged it off and not thought much of it. They were rather surprised when the Angel showed up a day or two later.

"Hello Dean, Sam," he said almost uncertainty.

"Hey Cas, what is it?" Dean asks.

"Well, I thought we should try and find some way of defeating Amara. Now that Lucifer is no longer an option."

"He never was an option in the first place."

Castiel got a slightly disgruntled look on his face and said in a mocking voice, so much different from the usual, "I know. It all seems so silly, doesn't it?"

Deans head jerks back in surprise and Sam asks, "Cas, are you alright?"

"Never better," The Angel says pushing past the brothers.

That one had been odd. He could almost swear he'd heard someone say that to him before, and that wasn't even the weirdest one.

Sam hadn't done anything that day. He was holed up in his room thinking over his conversation with Lucifer. It had shaken him but he was glad it was over. He heard a knock at the door and asked, "Who is it?"

"It's Castiel, can I come in?"

". . . No."

"Please Sam. You shouldn't stay in your room all day."

"Did Dean put you up to this?"

"No . . . okay yes, but he's worried. We both are."

"No, Cas. I just . . . I just need to be alone right now."

"Come on, Sam. Pay attention to me. I'm bored," The significantly different voice whines.

Sam freezes before carefully answering, "Go bother Dean, I'm sure he'd be happy to see you."

A few seconds pass before he hears the sound of receding footsteps.

Sam frowned. He had heard that before. It had been years but he remembered where he'd heard it. It was in a library watching over someone they thought was going to be killed. His blood froze. It had been his hallucination of Lucifer who'd said it. There was no way . . . nope, none at all. His mind drifted to the other times similar things had happened.

"Hey there Dean, Cas," Sam said walking up to the two men currently hunched over books.

"Hey Sam," his brother acknowledged him.

"What are you two doing?"

"Researching ways to kill Amara," Castiel answered.

"Find anything?"

"Nope, not gonna give up though," Dean says.

"Do you need any help?"

"Sure, you can help Cas with what he's doing."

Sam walked over and sat down next to Castiel, picking up a book and starting to read through it.

A few minutes later Castiel said, "You know we wouldn't have to do this if Lucifer—"

"No, Cas. Having my brother say yes to the Devil is the last thing that's gonna happen."

"I'm just saying Dean; this would go a whole lot faster if—"

"Shut up, Cas," Dean said standing stiffly, "I'm gonna get some beer, want any?"

Both Sam and Cas nod and the Angel says, "He said shut up to me," in a voice that sounded nothing like what Sam was used to.

Those words . . . he'd heard them before, in that same library. His eyes widened as he flashed back once more.

It had been a few days since the cage and Sam and Castiel were researching Amara.

"This is impossible," Sam says setting his book down and running his fingers through his hair.

"No, Sam, it's not. We'll find a way."

"Really Cas? We've been at this for days now and haven't found anything even remotely useful."

"What is that saying you humans have? Ah, where there is a will, there is a way. Don't worry Sam, it'll all work out in the end."

"You think?"

"I would never lie to you, Sam."

The significance of those very specific words then struck him. Sam stood up stiffly and walked out into the main room.

"Hey Sam. What's up?" His brother asks seeing the look on his face.

The younger Winchester stalks up to Castiel and drags him out of his chair, forcing him against the wall.

"Sam, what are you doing?" Castiel—no, Lucifer asks.

"I know it's you Lucifer, you can stop pretending," Sam says, his voice filled with spite.

"Lucif—Sam what are you talking about?" Dean asks.

Suddenly Sam is thrown back and Lucifer brushes off his overcoat.

"Cas, what's going on?"

The Archangel turns to Dean with a chilling smile and says, "Cas is—he's gone. I run the show now."

Dean's face opens into a shocked expression and he whispers, "Lucifer."

A predatory grin appears on the Devil's face and he says, "Oh, this is going to be so much fun."

So, thoughts? I'm not the best writer and would love if any of you would point out things that could help make it better. Just please don't be unbearably mean about it, I'm only human. And in case anyone is wondering, yes I used Levi!Cas's lines near the end.