Dean was seriously starting to question if Sherlock slept. When he awoke, (which for once was earlier than Sam), all he found was a note on the coffee table in the same sharp print that filled Sherlock's books.

Out to run errands. Be back by 10. SH

Dean dropped it carelessly back on the table and rubbed his eyes. Ugh. Too early. He usually had nightmares, but they weren't bad at all last night. His dreams were weird. Something about going on some date… only it was in a… volcano, or something? Whatever. Sometimes dreams had no meaning.

He checked the time. 8:00. That was lots of time. Besides, Sam needed his sleep after today. He wouldn't wake him until 9:30, at the earliest. He went into the bathroom and splashed cool water in his face, looking up into the mirror. Off to go summon an angel with a maniac. Sounds fun, he thought sarcastically. He didn't even know if angels were real, and certainly not how to protect himself from them. But he trusted Sherlock. I mean, not in the emotional frenship sense, obviously, but because the angel could kill him too and he was a genius, he would come up with some way to stop it.

He turned out of the bathroom and stepped outside. The fresh spring air was refreshing, and you can never really be sure when the next good day would come, so just for the heck of it, and since there were no other cars in the area, he washed the impala. He really liked washing her, actually. The smell of the soap, the spray of the hose, that fresh black sheen it got after like it was brand new. Well, not brand new, but not completely broken down either. When he did it, time was meaningless. He wasn't young, he wasn't old, he wasn't in the middle of something, he was just washing the impala. Like how it's always been. Like how it'll always be.

Needless to say time being meaningless meant time got away from him, and by the time he had finished, a taxi pulled up to the driveway (which nearly surprised him, as it hadn't really occurred to him that he could have taken the impala, but he could have, easily) and Sherlock stepped out, his tailcoat flapping in the april wind. He was carrying a rather large suitcase, and he was slightly bloodstained.

"You didn't take the impala." Dean identified.

"It's apparently your 'baby', it couldn't have been an act of kindness and respect?" he asked as he walked up the hotel driveway.

"No," Dean replied.

"Mm, you're right." Sherlock agreed, heading inside without him but turning to face him as he reached the door. "Honestly, I think that car is rather repulsive and I much preferred a taxi."

Dean rolled his eyes as he followed him inside. Sam was slowly rousing, rubbing his eyes and stumbling out into the living room, as Sherlock laid his suitcase out across the table.

"Slept in Samuel?" He asked, putting in the code for the locker-style lock on his suitcase.

"Hey, you have no right to bitch about it, seeing as how you're the one who tortured me," He responded through a yawn. He tousled up his hair (making Dean have to bite his tongue) and stepped up with Dean to look over Sherlock's shoulder.

"What's in there?" Dean asked.

"Anything we'll need and whatever I could find." he responded. His eyes glistened with wonder as he undid the final clips and opened the case.

Inside were thick, intricate chains a deep, wavering shade of black and red, and a bottle full of a brownish-black liquid. "The bottle is holy oil from Jerusalem. If we form a ring of it and light it, he will be trapped inside, doomed to die if he touches the flame. Based off an old hebrew myth. The chains are also coated in holy oil, and are made of blessed metal, based off the myth that angels can be killed with a holy blade, that it's the only thing that can take hold of its true form. It's also coated in lamb's blood, based on another old piece of lore that angels could not go into any houses which doors have been splattered with lamb's blood. Don't worry, they're not wet. I dipped them in fast-drying liquid plastic so they could be reused. It's all logic, but it should work."
Dean chuckled slightly. "Uh, wow." He said. "I gotta say it's impressive. How do we summon one?"

"It shouldn't take more than a basic incantation, a few sigils and a bit of blood."

Dean nodded, "Alright. Let's go!"

Dean drove, but he wasn't really in control. Sherlock was telling him every turn to take, every place to stop. They drove for a while, the houses getting more and more sparse until they were in the middle of nowhere. Finally, at (yet another) dilapidated old warehouse in the middle of the tall weeds, he told him to stop. That's where it would happen.

Inside it wasn't that dark, because of the massive hole in the ceiling casting a light down. As soon as they were inside, Sherlock was setting up. He found a chair in the corner, and brought that to the middle, creating a ring of holy oil around it. He painted a few sigils along the floor, too. Sam and Dean didn't really know what was going on until he handed them the chains.

"Now, you two stay in the dark as soon as it starts. I have a plan."

Sherlock explained quickly. It was incredibly simple, for him, anyway, but they both thought it was perfectly likely to work. It wasn't like they had any other option.

Sherlock set a wooden bowl outside of the circle, the opposite direction of the door. Dean pulled out his knife, beginning to cut into his palm.

"What are you doing?" Sherlock demanded before he could make the cut.

"You said it needed blood!" Dean rebutted.

"You do use your palm on a rather daily basis, you know. You may as well just cut off a finger."

Dean rolled his eyes and pulled the knife away from his hand. "Well, why don't you do it, then?" He said, thrusting the knife in his direction.

"Certainly," He responded. He swooped in and grabbed the knife, rolling up his thick, trench coat sleeve. He pulled up the knife and cut very carefully along the dead center of his forearm.

"The key is to sever the radial artery. Harmless, less painful," He held up his arm, and the blood easily poured. "And much more efficient than the palm."

"Yeah, no need to talk down to me, I've been doing this all my life." Dean replied angrily, but Sherlock ignored him. He let the bowl fill before he pulled a bandana out of his pocket and tied it over, barely even wincing. He rolled down his sleeve, excitement like a fire in his eyes. "Alright. Let's begin. Now I must confess, this may not work. this is an easier, safer incantation, however the angel comes of its own free will. On the occasion that it chooses not to, we may have to re-do this"

Sam and Dean nodded, then backed away, ready for the plan, as Sherlock began reading the incantation. The words of a language they didn't recognize rolled deeply off his tongue, still with a slight British accent. "Rah ah gah ee oh es, vee nu nohno kee ah seh peh teh poh ah ma lah deh zod."

They waited, listening for any sign. A second passed. Another. Another. Their anticipation already built up, Sam and Dean nearly jumped when the door broke open.

They couldn't tell if it had worked, because he didn't make any sort of angel entrance. He looked human. He had bright blue eyes, messy dark hair, and an intense face. He wore a suit with a sky blue tie and a beige trench coat flowing behind him. Although, the way he came, his stride long and confident, Sam and Dean almost believed it. They stayed in the shadows.

The angel approached Sherlock. Before he got the chance to speak, Sherlock stabbed him right in the chest.

However, his eyes widened with surprise as the angel reached up slowly, pulling the knife out of his chest and letting it clatter to the ground. There wasn't any visible pain at all. There wasn't even any blood. Sam and Dean shivered, hoping it would still work.

"I'm afraid, if you're trying to kill me, that's not going to work." He said. His voice was deep and gravelly.

Sherlock looked horrified for another moment, before it disappeared completely, replaced by his analytical, over-confident smirk. "I know," He said. Their que.

Sam and Dean sprung out of the shadows, each holding one end of the chain. They threw the middle over his head and pulled him back into the chair, securing the chains behind him. He struggled angrily against them for a moment, before looking up, confused.

"What is this? Release me immediately."

"Sorry, pal, can't do that," Dean said. "We need your help I'm afraid."

"But first," Sherlock said, a thrilled smile on his face. He bent over to see him better, his hands on his knees. "Look at you. An angel." Ignoring his pulling against the chains, Sherlock pulled his shirt and trench coat away to see the wound, rather high on his chest. After a moment, he pulled up his head and checked the pulse on his neck.

"Fascinating," he sighed, absolutely enthralled. "Most creatures that require vessels' hearts stop when they are killed, and they continue using the possessed human as a puppet, but you, oh, you're different. I cut right through the heart and diagonally to the pulmonary arteries, and yet your heart is still beating as though nothing has changed." His voice softened, marveling at the angel. "Arteries and veins kept in place by angelic grace alone, totally indifferent to physics and biology." Dean and Sam glanced over at each other. This was getting a little weird.

"Why have you summoned me here?" The angel growled.

"A few reasons. One, simply because I've never seen an angel before. Two, because we require your help."

"No," he replied immediately.

"Ah. Oh well." Sherlock said immediately, not really even caring.

"Dude, not 'oh well'! This is not a time for experiments!" Dean replied. "Don't we gotta call your brother?"

"Have to," Sherlock corrected. "And just give me five minutes. I won't kill him, and he's not going anywhere."

Dean growled.

"Five minutes," Sam spoke up. "But we'll be keeping an eye on you."

Dean reluctantly pulled his eyes away from Sherlock and followed Sam to another corner of the warehouse. There, they talked about what was going on and what they thought was going on as they reloaded all the weapons on their person. Sherlock, on the other hand, was using every moment with precision. This was the opportunity of his life, and he was practically giddy.

"My, my, where to even start? How about your name?" He asked, a grin across his face.

"And why would I tell you anything?"

Sherlock pulled a knife out of his jacket to answer his question. "Blessed knife. Not as good as an angel blade, but it'll probably hurt like Hell, which I doubt you're used to." He looked at it as he twirled it in his hand, before looking back up at the angel. "What is your name?"

He looked at Sherlock, then down at the knife, then back at Sherlock again. It probably wouldn't work, but he wasn't willing to risk it.

"Castiel." He answered gruffly.

"How much can I do to you, Castiel?" Sherlock asked eerily. "Without you dying? How many pieces could I cut you into? A dozen? A hundred? A thousand?"

Castiel scowled upward at him as he began to pace back and forth. "You cannot kill me." He answered.

"I know." He responded. "That's what's amazing about you." his voice softened with wonder. "A blank canvas I don't have to be afraid of tearing…" Slowly, he created a slash along his cheek, finding his assumption was right. It was red with blood but didn't bleed, held in place by non-existant skin. Cas hissed, still in pain.

"What are you?" Castiel growled. "Why are you doing this?"

"I am Sherlock Holmes," He answered softly, not actually mentioning his species. "And I'm doing this because I want to know everything about you. What you are, how you act, and how you die."

"A scientist, then?" He asked, beginning to formulate a plan.

"You could say that." Sherlock answered, a smile crossing. He was getting it.

"Have you ever been possessed?" He asked.

"Demonically, once." Sherlock said, beginning to figure out where he was going to.

"And angelically?" Cas asked. A smile spread across Sherlock's face, his eyes bright with excitement.

"No," He answered honestly.

"A useful experiment, if you would agree." The angel said, his face still serious.

"Definitely." Sherlock said.

"I have your consent then?" He asked. Sherlock knew it was a terrible idea. He ought to call Mycroft, he ought to just save the world and get it over with. But the question overwhelmed him with desire. Unable to stop himself, he breathed the forbidden word out his crooked smile.

"Yes."

Dean and Sam's eyes flicked up as they saw the bright blue light. They watched as it seeped from the angel's sky eyes into Sherlock's cold, icy ones. They leapt up.

"Hey!" Dean barked. But it was already done. The now empty body with dark hair and a beige trench coat fell limp and dead in the chair and Sherlock's face was monotone. He leaned up slowly. But it wasn't Sherlock. It was someone different entirely. His pose was straighter and his eyes less reading as they looked around the room. Warmer, too. This wasn't the same psychopath, it was an angel in the body of Sherlock Holmes.

Slowly the angel rotated his head back and forth, stretching its neck, then reached out his hand. Slowly, his thin pale fingers unfolded and rolled back into a fist as the angel looked forward, the determination of an unquestioning soldier in his eyes.

He looked down at his previous form with something between pity and disgust for a moment. He reached into his limp sleeve and pulled out a thin blade, slipping it up into his own sleeve.

Dean and Sam stood awed for a moment. Dean was the first to make a move. He reached rapidly into his jacket and pulled out a lighter. He flicked it on and threw it forward.

Immediately it caught. The ring of holy oil Sherlock had set down illuminated in a flickering golden fire, surrounding Sherlock. He attempted to back away, in shock, but was soon surrounded by the ring of fire. Dean smirked as he looked around him in alarm and anger. Got him.

The angel scowled. "I was considering sparing you, but I find that more and more unlikely," he growled. His voice was different, too. Less manipulative, more set in stone.

"I'm sorry, but we really do need you. Just hear us out." Dean said.

"What could possibly be this important?" He asked them.

Sam and Dean looked at each other, wondering who was going to say it first. Sam nodded at him to do it. Dean turned back to the angel, a grave look on his face.

"Lucifer." He said softly. The angel didn't react in a way that was over-the-top, but it didn't take Sherlock to figure out he was horrified. His eyes widened and his fingers slowly curled. His head shook.

"Lucifer has been locked up for thousands of years," He denied.

"Yeah, well, we interviewed a knight of Hell, and-"

"The knight of Hell was on Earth?" He asked, even more shocked.

"Yes. And it said that Lucifer would rise."

The angel didn't speak, looking around at the ground, with thought in his eyes. "I have to report this to heaven immediately-"

"Now, hold on just a second. A couple things first. One, we need Sherlock. He can help us, so we can't have you walking around wearing him."

The angel paused. "First, who are you?" He asked.

"I'm Dean Winchester, and this is my brother Sam," Dean said, gesturing to himself then to his brother in turn. Sam nodded.

"Listen, It's a bad first impression, I know," Sam told him, kindness in his eyes. "But we're not your enemy! We just want to make sure that Lucifer doesn't rise, like I'm sure you do too."

"So, you're asking me to trust you?" He asked, disbelieving.

Sam shrugged. "A lot, I know, but genuinely, we need your help," He said. "Besides, we can't hurt you with anything we've got, so there's no point in running off."

"And why shouldn't I just kill you all now, then report this to heaven?"

Sam didn't answer. Dean looked at him, waiting for something in hope. Honestly, there was no reason why he couldn't. And why he couldn't report them to heaven? Mycroft needed… something. Quite frankly, Sam was stuck.

The angel nodded at that. He looked back at his old body, a brilliant blue light shimmering over his eyes combined with the flickering orange of the flame in front of him. "Put out the holy fire." He commanded.

Dean looked at Sam, who seemed to know what to do. Sam nodded, and the both of them stomped out the fire until it was all the way gone. The angel stared at the body. He placed his hand on its cheek, and his eyes went blue. The light seeped from Sherlock's eyes to the other man's. It was amazing to see them light up, from off to on, from asleep to awake, from dead to alive.

When the blue stream ended, the man was sitting, living in the chair and Sherlock fell gasping to the ground, his eyes wide. Dean raced over to him.

"Sherlock, are you alright?!" He demanded.

"What's my blood pressure?" He panted to himself. He pressed his thumb along his wrist, feeling his heart beating rapidly. He winced, his head killing him. He patted his jacket and managed to fish out another black leather journal, with fresh new pages. He pulled out a pencil and started writing before he could even catch his breath.

"What are you doing?" Dean asked, stepping back.

"Angel possession," Sherlock panted. "I need to record every detail while I still can."

"You need to call Mycroft." Dean told him

Sherlock scowled at him, but he was right. He pulled his phone out of his coat. He caught his breath as it rang, rubbing his temples. It wasn't pleasant, being the vessel of an angel, but it was so worth it. Just to know the information.

"Found the angel?" Mycroft asked from the other side of the phone.

"Yes," Sherlock answered as he stood up.

"You're out of breath. Why?" he asked.

"I'm not out of breath." Sherlock lied.

"Yes, you are, and you're lying about it, too. What did you do, Sherlock?"
"An experiment."

"Specifically?"

"Angelic possession. I had to know what it was like." He grumbled.

"Oh, brother mine, you are so incredibly stupid sometimes," Mycroft sighed, rubbing the bridge of his nose. "What part of 'safety' did you not understand?"

"It doesn't matter, I'm alive, aren't I?"

"This time, you are. But if my predictions are correct, and they typically are, the path gets harder from here. If you'd like to survive the week, at least, Sherlock, I highly suggest you be more careful."

"Very well…" He grumbled. He did it to end the brotherly conversation, not that he actually intended to stop doing things his own way. "What do I need to do next?"
"Find out what the angel knows, by any means necessary. But no permanent damage and, really this time, be careful."

"Fine." Sherlock answered. He hung up the phone and stuck it back in his coat. He turned to the angel.

"He says to get information. By any means necessary." He found the angel blade was still in his sleeve and let it drop, looking at it as he caught it. Castiel's eyes widened with visible fear. Slowly, he raised the knife.

"Sherlock." Dean stopped him. Strangely enough, he didn't shout. He said it softly, a gentle warning. Keep an eye on him. Mycroft's words rang in his head. For my sake, and for everyone else's. Sherlock is dangerous, and emotional, and he has an awfully bad habit of destroying everything he touches. It'll be bad for everyone, and most importantly, for himself. Dean's face remained stark. He began to see some meaning to this enigmatic comment.

Sherlock turned to face him.

"We talk, then torture," Dean insisted. "We do want him on our side."

Sherlock sighed, lowering his arm. He looked at the angel, disappointed. "Fine," He said. He took a step back.

"Well, I'm not gonna turn this into a chick flick, but the truth is, we're not gonna be able to help each other…" He bit his lip, knowing this was stupid. He held out his hand to Sherlock. "The knife."

"What?" He demanded.

"Dude, the knife!"

"Why?"

"I've got a plan!"
"And I'm supposed to trust your imbecilic plan?"

"Just… trust me, will ya?" Dean said. Sherlock rolled his eyes and handed him the knife by the hilt. Dean kept it close as he went around the back of the chair. He undid the chains.

"Dean, what are you doing?!" Sam demanded.

"Trust me!" He replied. He loosened the chains, he let them fall to the floor, but he kept them tied. They formed a ring around the floor. The angel could stand and be more comfortable, but he wouldn't be able to leave the ring.

He went back around and held the blade by the dull end, handing the angel the hilt. Before he could take it, he pulled it back slightly. "Don't stab me," He told him, then offered it again. His heart was racing. This was a horrible idea. The angel took the knife and slid it back up into his sleeve.

Dean stepped back. "There. Now we can't hurt you and, hopefully, you can't hurt us. Now we just wanna talk."

"I have to report this to heaven," He said.

"Yeah, okay." He said, ignoring that statement. "Let's start here: what's your name?"
"His name is Castiel," Sherlock interjected.

"Alright," Dean said. "Castiel, huh? Okay. What do you know about Lucifer?"

Sam looked at his brother. It was rather shocking, what he was doing. He was usually the soldier, not the diplomat. What happened to shoot first, ask questions later? He was actually being smart. But… trustful. He had to confess, he wondered why.

The angel was silent for a moment. "Only that he can't be escaping." he said finally. "He's been locked in that cage for thousands of years. Why would he be able to get out now?" Sherlock already had a notepad out, taking down what he was saying.

Sam shook his head. "I don't know." He confessed. "Do you know anything about knights of Hell?"

Castiel nodded. "Yes, you… mentioned they were on Earth."

"Yes." Sam responded.

"They are… specialized demons, in a way. Chosen specifically by Lucifer to carry out his will. With no orders from Lucifer, they never roam the Earth. They are extremely dangerous. The only way they can be killed is with someone withholding the mark of Cain wielding the first blade, which is a power that hasn't been released on Earth for just along the same time Lucifer has been in the cage." He hesitated. "How can you be so sure he is rising?"

"We're not sure." Sam said.

"Yes, we are." Sherlock said. "My brother is convinced, and while he is completely obnoxious he's also extremely intelligent, maybe even more so than me. Lucifer will rise unless we stop him."

Castiel swallowed. "Well, as far as information, that's about all I know. Lucifer has been caged since before I was born, and nobody even speaks his name in heaven. Why did you need all this, anyway?"

Sam shrugged and shook his head. Dean interjected and told him "We don't really know. We're sort of helping out a higher up."

"Who?" He asked, out of curiosity.

"Guy named Mycroft," Dean responded.

"As in, Mycroft Holmes?" He asked, seeming surprised.

"Uh… yeah." Dean said, confused. "You know him?" A spark of anger flickered behind the angel's eyes and his lip curled into a sneer.

"Everyone does. He's basically ninety percent of Heaven's government." he growled.

"Oh, of course he is." Sherlock said, rolling his eyes. "I swear, I will pay you if you find a place my brother has been to that he hasn't taken over."

"Least he hasn't got Earth," Dean chuckled sarcastically.

"I wouldn't be so sure," Sherlock admitted, not looking at him. Dean raised his eyebrows. Well.

"So, that's everything you know?" Dean asked.

"Everything of importance," He responded.

"Well, thanks," Dean said genuinely. he turned to Sherlock. "Let's make the call."

"On it," Sherlock said. His phone was already out.

"Done so soon?" Mycroft asked.

"He didn't know much," Sherlock told him.

"Just out of curiosity, who did you get when you did the angel summoning?"

"Castiel," He answered.

"Oh, well, he wouldn't know, would he?" He asked rhetorically

"And why's that?"
"He's barely older than a teenager, he wouldn't remember anything about Lucifer's antics. He's been in the cage his whole life and several thousand years previously."

"Ah, yes. I suppose that would leave him with little information. He did, however, say you were ninety percent of Heaven's government."

"Now, ninety is a bit of an overstatement." He confessed. "But onto more important matters, brother mine. Are you going to tell me the information?"
"Why would I tell you over the phone, you of all people know the calls are monitored."

"Trust me, Sherlock, it's easier this way."

"Why can't I just come see you? What happened to safe?"

"Stop asking questions, Sherlock," Mycroft snapped a little too quickly. "What did Castiel say?"

Sherlock hesitated. "Hang on a moment. I have to call you back."

"Sherlock-" but he was cut off as the phone was hung up. Sherlock stuffed the phone in his pocket and put away the notepad.

"We have to go." He said.

"What? Why?" Sam asked.

"Something's wrong," Sherlock said certainly. "Mycroft is in danger, we need to return to the white house."

"We can't just go!" Dean said. "He'll run off!"
"Fine, then I will," Sherlock said, adjusting his coat and starting out the door. Dean and Sam looked at each other. Sam looked at Cas. We can't trust him alone. Dean looked frantically over at Sherlock. We can't trust him alone either.

They both gave each other a conflicted look, before they knew they'd have to split up. "I'll take Sherlock," Sam said finally.

"Okay," Dean agreed.

Sherlock ran off after Sherlock, who was heading out to the impala. He had nearly taken off by the time Sam reached the car. He had to close the door as the car was moving. That left Dean alone with the angel. They looked at each other for a moment, awkwardness in the air. Finally, Dean just briskly nodded and went over to the wall beside him. He sat down, his back against it, and cleaned out his gun because he had nothing better to do. There they sat in silence, as Sherlock and Sam drove back to the whitehouse. Neither of them spoke, Sherlock going way too fast and across deserted roads until they finally arrived.