AN: For biggreenbug on Tumblr, who prompted 'Third Man Phenomenon.' This got way, way out of control and went in an entirely different direction than what I had originally intended. Oops. I would like to continue this and build up Dean and Cas's relationship.

.-.-.-.-.
Familiarity
.-.-.-.-.

Dean pulled his coat tighter as a shiver ran down his spine. The feeling was back. As if he wasn't quite alone. He shook his head. Of course he wasn't alone. He was on a 'small research trip' with his brother. But, it felt like there was one more person.

He took a quick glance around the old room, just to be sure. Nothing. No one.

How did Sam manage to talk him into this? Sam was an archaeologist, but not the sort that specialized in old civilizations. No, Sam had to be into the occult. His baby brother actually believed in the nonsense that was the supernatural and sought out locations with a rich history pertaining to the occult. Sites of supposed devil worship, monuments to gods, monsters, and demons, and, of course, old Victorian houses that were once inhabited by wicked witches.

He wanted to say he was thoroughly creeped out, but he felt comfortable. Safe. He shouldn't be feeling this way about a creepy, old house. With every step he took, an ominous creak resounded. Cobwebs were everywhere. And he was certain there was a scraggly-looking cat wandering silently about the house.

He mentioned the cat to Sam, and Sam immediately burst into a happy tirade about how Dean was so lucky to have seen the witch's familiar. Dean insisted it was just a mangy old cat, but nothing he said could sway Sam's belief.

Out of the corner of his eye, Dean caught sight of the cat. He quickly turned to find a pair of bright blue eyes staring at him. In the fading light of the day, he couldn't tell if the cat was black or dark shade of brown. Dean stared at the cat. If he could catch it, he could bring it to Sam. Prove that it was just a cat. Just some stray that was living in the old house.

Dean stepped forward, and the cat stretched before turning and leaving.

'Wait! Here, kitty-kitty,' Dean called softly. He knelt down and offered his hand to the cat. He smiled as the cat looked at him in vague interest. 'Yeah, c'mon. I won't hurt ya'. Might even have some nice tuna or something out in the car.'

The cat tilted its head as it regarded the human. It turned and trotted out the room and down the hall.

'H-hey!' Dean followed the cat into the hall. He looked around, but couldn't find any trace of it. He scratched his head. All the other doors were closed. Where could it have got to? Was there a hole in the wall? A quick inspection proved there was no hole or crevice that a cat could fit through.

He crossed his arms and glared at the empty hall. He refused to believe Sam was right. He did not just see a familiar or ghost cat or whatever it was supposed to be.

The feeling of someone else being right next to him was stronger than ever. He felt safe. It was annoying. His heart beat faster as he surreptitiously looked around. Just in case he wasn't alone, he didn't want to let the intruder know that he knew. He casually placed his hands behind his back, ready to whip out his gun. If Sam was behind him, then Sam would just tease him about being paranoid. It had happened on more than one occasion. He'd get jumpy and point his gun at any little sound.

He spun and pointed the handgun at nothing. He edged back into the room he had originally come from. It was empty. He let his arms fall to his sides. Now what?

'Better find Sammy,' he muttered to himself as the comforting feeling faded.

He heard a soft click come from the hallway. He turned and cautiously made his way to the hall. He looked around and noticed a crack in the wall. One of the panels appeared to have popped loose. Dean nudged it open further, and it swung out soundlessly. The panel opened to reveal a small passageway. He could make out a soft flickering light at the end of the passage.

So there was someone there. Dean wasn't just paranoid, after all. Leading with his gun, Dean entered the small passage. He gasped as the panel shut behind him. He turned and pushed at it. It remained shut.

A sharp meow echoed behind him, and Dean looked to the flickering light. So that's where the damn cat got to. He quietly made his way down the passage, finding a small room at the end.

Dean stared in awe. Old books lined every wall. Jars with faded labels sat on every available surface not infested with books. A quick glance told him no one was in the room. And it looked like no one had been in there for quite some time.

He sighed as he safetied his gun and tucked it into the back of his jeans. He frowned when a thought hit him. Where was the light coming from? There were no candles, no light bulbs. Just a low glow. Looking around in confusion, he found the source.

A book lay open on an old table. Dean approached the book, not quite believing his eyes. The pages were glowing. He reached out to touch it and quickly jumped back as the cat landed on top of the book.

'Shit! Fuck! Y-you fucking evil monster!' Dean shouted.

The cat stared at Dean. It got off the book and sat just behind it. It looked from Dean to the book and began purring.

Dean looked around. He had to be going crazy. If he didn't know better, he'd think the cat wanted him to read the book. He shook his head and shrugged. 'Sure. Why the fuck not?'

He walked up to the book and stared at it. As far as he could tell, it was written in Latin. He startled as the cat meowed loudly at him. 'What? Am I supposed to perform a spell or something?' He said jokingly as he reached out to pet the cat.

The cat leaned into Dean's touch and purred loudly. It meowed again as it pulled away from Dean's hand.

Dean rolled his eyes. Why was he doing this? He should be leaving and finding Sam. This was more Sam's speed. Finding weird, old books that glowed and reading from them. He had to be dreaming. He had to have fallen asleep while waiting for Sam.

Since he was dreaming, what harm could come from reading from an old book? As long as no Candarian demons popped up, then he'd be okay. And if they did, he'd kill his brother, chop off his hand, and shove a chainsaw on his wrist. Good plan.

He looked at the book again and ran his fingers across the words as he recited them. He frowned when nothing happened. 'Right… Well, this dreams sucks,' he said to the cat. He looked up to find the cat missing.

'You're not dreaming,' a deep voice said behind him.

Dean spun around and pointed his gun at the intruder. Before him stood a man. He looked like he had just walked out of one of the old paintings hanging around the house. He wore a dark frock coat and trousers, and his tie was undone. Dark hair. Blue eyes. The same color as the cat's. 'Who the fuck are you?!'

'My name is Castiel.'

Dean laughed as he ran a hand through his hair. 'What the fuck…?' He was going crazy.

'You're not crazy, Dean. You have a very special gift,' Castiel said.

'Gift?' Dean repeated.

Castiel nodded. He walked up to Dean and laid his hand on Dean's, making him lower the gun. 'You are a witch, and I am now your familiar.'

Dean blinked. 'Yep. Still dreaming,' he said.

'You're not—'

'Well, I'm gonna find Sam,' Dean said as he headed back into the passage.

'But the book!' Castiel looked from Dean's disappearing figure to the book on the table. He huffed in irritation and grabbed the book. He found Dean struggling with the secret panel. 'It obeys your command,' he said. 'Tell it to open.'

Dean threw a glare over his shoulder. 'Fine. Open says me.'

The panel popped open.

Dean stepped out into the hall. 'Sammy!' he shouted.

'Dean—'

Dean headed off to where he thought Sam should be. 'If you're supposed to be my familiar, then shouldn't you be calling me "master" or something?' he asked conversationally.

Castiel hugged the book tightly to his chest. 'That is not the relationship between witch and familiar,' he replied. 'We draw from each other's power. It's more like marriage than master and servant.'

Dean stopped in his tracks, and Castiel ran into his back. 'We're married?' He looked at Castiel from head to toe. For a dream that decided to take a turn toward a whole new level of weird, he could certainly do worse. 'So, my subconscious wants me to settle down with a guy,' he said, raising a brow.

'I'm neither male nor female.'

'Uh-huh… Well, once I blow off some steam with Sam, you 'n' me can make this dream a little more interesting,' Dean said as he began walking again. 'If you change into a chick halfway through, I won't complain.'

Castiel blushed. 'N-no… I only have one human form. This…this is the vessel that was offered up when I was summoned,' Castiel explained. 'Though some witches and familiars do…do that, I uh…don't think we're quite at that stage…just yet.'

Dean rounded a corner and found Sam packing up his bag. 'Sammy!'

Sam looked up, smiling at Dean. His smile faltered when he laid eyes on Castiel. 'Um…Dean, who's that?'

'Cas,' Dean said dismissively.

'Castiel,' the familiar corrected. 'I'm his familiar. It's a pleasure to meet you, Sam.'

Sam stared at Castiel then at Dean. 'W-what…?'

Dean placed his hands on Sam's shoulders. 'I'll never get a chance to say this when I'm awake,' he said, 'but, Sammy… Your profession sucks. Between creepy mausoleums and dumping grounds for human sacrifice, I think I've had it. But I'm still gonna follow you around and keep an eye on you. Because I'm a glutton for punishment.'

Sam stared at Dean. He reached up and pinched Dean. Hard.

'Ow! What'd ya' do that for?!'

'Dean,' Sam hissed, 'you're not dreaming!'

Dean stared at Sam in shock. He looked at Castiel, who smiled helpfully. 'But…' Everything went dark.

.-.-.-.-.

Dean opened his eyes and saw the familiar ceiling of the motel he and Sam were staying at. It was all a dream. A really fucked up dream.

'Dean! Are you all right?' Sam asked.

Dean sat up, scratching his head. 'Yeah… I had this weird dream…' He trailed off as he looked around the room and his gaze fell upon a certain dark haired man.

Castiel gave Dean a small smile. 'Good morning, Dean.'

Dean scrambled out of the bed. He became tangled in the sheets and fell to the floor. He pulled himself up and pointed accusingly at Castiel. 'Y-you! You're real?!'

Castiel nodded. 'Of course I'm real,' he replied in an offended tone. He was still protectively clutching the old book. 'But that doesn't matter, we need to ta—'

'You're real.'

'Yes. De—'

Dean shook his head. 'No. I just got Punk'd, right?'

Castiel frowned at the reference. He looked to Sam for help.

'No, Dean. This is really happening,' Sam said. 'Castiel explained, well, enough to me.'

Dean recognized the frustrated look on Sam's face. It was the same look he got when he had trouble translating an old text. His so-called familiar was holding out on Sam. He looked to Castiel. 'Okay… Let's say I do believe all this,' he said, waving his hand. 'Why me?'

Castiel straightened and smiled at Dean. 'You're special. It's in your blood.'

Dean sat on the edge of the bed and stared at Castiel. 'Uh-huh… What about Sammy? Is he "special," too?'

Castiel looked uncertainly from Dean to Sam. 'Yes,' he eventually replied.

'Then why not him? Why me?'

Castiel bit his lip. 'For all his enthusiasm, we are not compatible. A witch's and familiar's magic must be compatible.'

Dean glared at Castiel. 'Magic. Magic?' He shot Sam a doubtful look. 'I don't have magic. I'm not magic. I'm not a…a witch.'

'Actually, Dean…' Sam rubbed the back of his neck. 'You are kinda sensitive to the supernatural.'

'What.'

'I uh…' Sam let out a nervous laugh. 'Not all the places I dragged you to were haunted… I started testing you when I noticed how you got…jumpy at the places that were notorious for being haunted. I wanted to see if it was just the knowledge of what had happened, or if there was something else going on.'

Dean stared at Sam. 'I'm not talking to you anymore.'

'Dean—'

Dean held up his hand. 'No. Not talking.' He looked to Castiel. 'Are you a cat?'

Castiel's head hung slightly. 'She was dying from cold and hunger… I eased her way,' he quietly replied. He looked away. 'She was the closest thing I had to a friend after my last witch was…well…'

'She was lynched by the townspeople,' Sam supplied.

Castiel stared at the floor, nodding. 'I was unable to stop them.'

Dean sighed and looked away. 'Okay. I'm a witch. You're my familiar. So, now what? Do I have to go to witchy school or something?'

Castiel looked back up, a smile returning to his face. 'No. Nothing like that,' he said. He held out the book to Dean. 'You just need this. It's yours now.'

'What if I don't wanna be a witch?' Dean challenged as he crossed his arms.

Castiel lowered the book and gave Dean a confused stare. 'You don't have a choice in the matter. You were born a witch.'

Dean grimaced and took a deep breath. 'Can we call it something else? Warlock? Wizard? Sorcerer? Anything besides witch?'

'I don't understand.'

'Witches are girls.'

'Witches are men and women,' Castiel corrected.

'The term's changed a little over time,' Sam said helpfully. 'It's more specific to women now.'

'Oh.'

'Well, I'm not gonna be a witch or warlock or whatever,' Dean said as he stood.

'But you don't—'

Dean strode up to Castiel jabbed his finger at him. 'Just because I'm magic, don't mean I have to do magic. Keep your damn book.'

Castiel fidgeted and bit his lip. 'I suppose…that you have a choice in…'

Dean nodded, satisfied. 'Good. Now that that's settled. No more talk about magic. You,' he pointed at Castiel, 'should go do whatever it is you guys do. Have fun with your life.'

Castiel looked up miserably at Dean. 'I can't.'

Dean let out a short laugh. 'Come again?'

'I'm your familiar. You are my witch…er…warlock… Our energies are interwoven now,' Castiel explained. 'I can't leave. I'm bound to you until you die.'

Dean ran his hands over his face, looking anywhere but at the two other men in the room. 'I can't…' He shook his head and stared at the floor. 'I just… I can't do this right now. This is too much.'

'I'm sorry,' Castiel apologized. He flinched as the door to the motel room slammed. He stared helplessly at Sam.

Sam smiled encouragingly at Castiel. 'It'll be okay. Let him blow off some steam. He'll come around eventually.'

Castiel nodded. He noticed how Sam was eying the book. He hugged it tightly to his chest and glared. 'This is not for you! Find your own!'

Sam sighed in disappointment. He perked up as a thought struck him. 'Do you happen to know where I can find a familiar that'd match me?' he asked.

Castiel stared at the book in his arms. His brother had been without a witch for quite some time now… But, could he live with seeing Sam doting on his own familiar while Dean wanted nothing to do with him? Could he live with himself if he denied his brother the chance of having a witch again?

'I…I have a brother,' he eventually said. 'But the decision will ultimately be his.'