Sherlock and Supernatural Crossover. Sherlock's sister!readerxCastiel

Do Your Research

You answered the door. Three men stood there. One was in a trench coat, the other was really tall, and the last one was a dirty blonde.
"May I help you?" The tall one nodded. The blond smiled, eyeing me closely. The trench coated man seemed embarrassed by his comrade's lustful behavior.
"Yes, we're looking for a man named Sherlock Holmes, he was a friend of our dad's and-" I didn't need to hear his explanation.
"Follow me." I walked the men up to Sherlock's study. The shorter one gripped something in his pocket, I heard a small clink.
"Three men are here to see you." You said, flatly.
"Analysis?" He always wanted you to give him an analysis of anyone who so looked at him the wrong way. It had become like a game.
"They are American. Two seem to be brothers. I assume they lost their mother at a young age, and had an abusive, less physical, and more verbal, father. Father was a soldier. They do hunting, of some sort. One appears well educated, they both seem to have seen a lot of crap in their days. The shorter brother has severe depression and anxiety, afraid that he'll never truly be worthy of his father's legacy. His younger, but much taller brother, idolizes him. appears to fill the void in his life with sex and alcohol. The trench coated man is a soldier himself. He feels he is the protector of the brothers. His father was absent, and he had many siblings. Most of which I assume he has lost. Extremely religious upbringing, but now doubts that it all really matters. Most likely rebelled against his older siblings teachings." You looked over to the trench coated man, and noticed something behind his back. Odd. They looked like a pair of black wings! You shook off your growing suspicion.
"How the hell did you know all that?" The shorter blonde asked.
"Accents gave away that you were American. You all reek of gunpowder. You stand rigid, a common thing among abused first borns. You were raised as a soldier. Your brother copies your clothes. He is clearly younger, because despite his set form, he moves lightly. Your walk is almost like a march. It is unlikely your mother would have put up with this or put you through it, so she must've died. Leaving you with your father. Your brother has a formal greeting, meaning at some point he went to college, I'd assume Stanford, possibly Harvard. I say Stanford, because all the teachers teach that greeting. You have dog tags in your pocket, you held onto them earlier. You're afraid to let your father down, but feel you already have. I assume you're depressed because of that. Your brother feels the opposite, you know. Your friend in the trench coat, and um," you debated mentioning the wings, you decided against it, clearing your throat instead.
"He stands rigid like you, but is more alert. He is in formation standing. Like a soldier would be taught. His father left him and his family, I can tell because he has the need to protect you two. I saw it when I opened the door, he scanned the street for possible threats. He likely rebelled against his brothers, protecting you two." They stood wide eyed. They were in utter shock. You smirked lightly.
"Very good. Names?" The tall one spoke, the others stared.
"I'm Sam, this is my brother, Dean, and our friend, Castiel."
"Name meaning analysis." Sherlock ordered.
"Assuming 'Sam' is short for 'Samuel', meaning 'heard by God'. 'Dean' comes from 'Denu' meaning 'valley', name means 'Head of the valley'. 'Castiel' is two parts. 'Cas' is the root word in Latin meaning 'to fall', '-iel' is of or from God. Name means 'to fall from God' or 'to fall from grace'." Castiel shifted uncomfortably.
"Well. That's a bad thing, isn't it?" Sherlock stated bluntly, "You may enter." The men entered, you were worried about Castiel. His wings looked to big for the door. He was standing in the hall way.
"Are those going to be an issue?" You whispered as I passed, I had been pointing to the wings. He stared at you abruptly.
How can she see my wings? Wrung in Castiel's mind. He shook his head, and folded them, stepping into the room. You nodded. You stood in the doorway. Hoping Sherlock would allow you to sit in.
"What can I help you lads with?" Sherlock finally looked up from his paper.
"We're hunters-"
"My sister mentioned that, but continue."
"Yeah. Uh, we're hunters. He emphasized the word hunters like he was hinting at something. Sherlocks eyes widened. Odd.
"Leave." He instructed me.
"But Sherlock, I can-" You tried.
"Leave you stupid girl!" This stopped you in your tracks. Sherlock did and said a lot of crap, but calling you stupid hurt. You blinked your eyes, trying to stop from letting tears fall.
"As you wish. Nice meeting you Sam, Dean, and Castiel." My voice wavered uncontrollably. Sam looked back at me, apologetically. You left. You joined John in the kitchen.
"He couldn't do anything without me." You were only muttering to yourself, but John picked up on it.
"Sherlock didn't mean it. You know he has little patience. He's pretty much a psychopath."
"High functioning sociopath." You corrected. John nodded.
"Yes. That." He was right. Sherlock just had very little patience.

-Sam's POV-
What he said to his sister was really harsh. I mean, obviously she wasn't stupid. The words cut her deep, I could tell.
"So can you help us?" Dean's voice snapped me back.
"I can. I shall. But not a word to y/n." He was ordering Dean around.
"Wait, she doesn't know about this stuff?"I butted in.
"Of course not! She'd get herself killed!" He stood up, "I will help you during your time here. But leave her be. She may be ignorant, but it's blissful." He instructed. Dean nodded.
We needed the help. As we stepped out of the study, Cas pulled both of us aside.
"Something is different about that girl." He said, whispering to us.
"What do you mean, Cas?" I asked, Dean looked over his shoulder.
"She can see them."
"See what?" A worried tone lined Dean's voice. Castiel shifted.
"My wings." He finally explained. My eyes grew wide, and I could feel Dean's did too.
"I assumed she knew what you did, because she seemed unconcerned by the fact that they are there. We heard shouting from the study.
"Sherlock! I told you, I know what I saw!" She shouted, anger oozing out of every poor.
"You are seeing things! There are no such things as-" he whispered the next part.
She stormed out of the study.
"Everything alright?" I asked.
"It is to none of your concern, so yes." He responded.
"Y/n. Please show these men to the door. They can return at a later time." She nodded, still obviously upset. We followed her to the door, and when we exited, she followed, locking the door behind her.
"What are you doing?" Dean asked warily.
"We need more coffee. Sherlock drank the last of it, and me and John need something to help us pull another all nighter." She explained.
"All nighter, why?" Castiel seemed genuinely concerned for the girl's, who Sherlock had called y/n's, well being.
"To help Sherlock, of course." I was intrigued, we had started walking down the side walk.
"With what?" Dean asked.
"Work." She spat, clearly uninterested in conversation. She was a lot like her brother.
"So, what, is your brother psychotic?" Dean joked. She stopped rigid.
"He's a high-functioning sociopath. Do. Your. Research!" She practically screamed through gritted teeth. She continued, not saying another word.
"Not one for conversation, huh?" Dean had a flirtatious tone to his voice.
"No, I am not. Now drop that tone." She had picked up on it. Dean was stunned, and his cheeks were rosy. I chuckled, and in a few steps she turned into a store.
"Good night!" I called, as she opened the door to the store.
"Bonne nuit." She called back, uninterested, as she stepped into the store.
"She was..." I started.
"Hot." "Charming." Castiel and Dean had spoken at the same time, clearly two different minds entirely.
"I was looking more for curious, but those work, too." I finally said, as we walked back to the hotel.