Sherlock and Supernatural Crossover. Sherlock's sister!readerxCastiel

Game Time

You had his slacks on, your hair stuck in a hat. Your coat was an old coat of Sherlock's. You looked like every other male in the pub. More importantly, you looked just like her type. A woman, who even wore the same dress as in he video, sat down next to you.
"So, what's your name, little lady?" Y/n said, in your best gruff voice you could do.
"Myla. And you are?" You assumed she was using the same flirtatious tone she used with all the victims. You held out your hand.
"Castiel, Castiel Winchester." It was all you could think of. She shook your hand, smiling at you.
"So, Castiel," She already loved using the name when she spoke, "What do you say that you and I, head up to the Callipher on sixth, and enjoy ourselves. This is my last night in London, Castiel." every time she said the name, you couldn't help but want to smack her.
"Deal." She stood up, and went to exit. You saw Sherlock at the door. As she exited, you knocked into him 'accidently', handing him a paper. You followed the woman. Sherlock opens the note. He reads it, sets it down on the table, and walks calmly out of the pub. Dean grabbed the note. The Winchesters follow him.
"Uh, Sherlock, what is it?" Sam asked slightly worried. Dean handed him a note. Sam read it aloud.
"I'm going to jump. It's all a trick. Six. Y/n. What does all this mean?" Sam ran to catch up to Holmes and Dean.
"TAXI!" Sherlock shouted and a Taxi pulled up, he hopped in and the Winchesters hopped in right behind him, "Callipher on sixth and main." He said calmly to the driver. After a couple minutes they came to an abandoned building. Sherlock jumped out of the car. They ran inside the building, they could see where you were, but Sherlock stopped them from going in.
"We need a confession. Lestrade will be here shortly." He whispered when Sam tried to push through.
"So, you are going to let her get killed?" Sam whispered, but shot back.
"She'll be fine." Sherlock assured. Wings flapped silently behind them. Dean and Sam turned to the sound.
"Castiel, I assume." Sherlock stated.
"How'd you know?" Dean asked, hushed down. They all turned their attention to the sound of voices in the other room.

-Castiel's POV-
"So, Holmes sent in his own sister in as bait. True psychopath, that man." Myla Crofet. She must be the killer. Y/n wasn't even worried. She was pushed against the wall by Myla.
"My brother didn't send me. He wouldn't even take your case! Too boring, he said. He was right, you aren't clever. You are just a sad little girl." Y/n spat at Myla.
"Too bad. I kinda liked you." I wanted to punch this Myla. Dean held me in place. Y/n scoffed. I assumed Myla started choking y/n after that. I turned my head away, I wanted to barge in. Why?
"The bloody hell?! Why aren't you dead?" Myla screamed. Y/n laughed at her frustration.
"You truly are stupid. You don't even know why the way you're killing is working! I'm a female you arrogant twat!" Myla became enraged at y/n's words. Sherlock turned the corner into the room.
"She's right. That's what makes this game rather boring." The sound of Myla falling to the ground. I followed Sam and Dean into the empty room.
"Where is that idiot detective?" Y/n was standing over Myla's body.
"I'm right here." A man, I assumed to be the idiot detective, cuffed the woman lying on the ground.
"Moriarty is quite the fan of you, little lady. Sherlock? Old news. You? You have something different.  Even your brothers know it. You're a much more fun play thing." Y/n seemed angered.
"Moriarty is dead." Sherlock insisted. Myla laughed, she snapped his head to look at him.
"Your sister might think a little differently." Y/n looked away. Sherlock looked at her, and she looked away.
"What's going on here?" Lestrade eventually asked. I was wondering that myself.
"You didn't." Sherlock almost seemed to be pleading.
"No. I didn't. But I knew." She responded. Sherlock seemed angry.
"What is going on here?" Dean repeated Lestrade's question.
"My sister is protecting a consulting criminal!" She rolled her eyes at the name.
"What? That's preposterous." The detective said.
"No. It isn't." A man seemingly appeared out of nowhere, smiling.
"Moriarty." Sherlock accused.
"Guilty!" He sang, "Too bad your sister isn't. Could've been so much fun! Like you and I had Sherlock!" The man was standing only a few feet behind the younger Holmes. Lestrade and Sherlock locked their weapons on him. Moriarty rolled his eyes.
"Oh, how boring. Tell me Sherlock, where's your pet, Watson, isn't it?" Moriarty pulled a gun, and aimed it for Sherlock's sister.
"Cas! Help her!" Dean shouted.
"Shut up, idiot. He can't." Y/n said. I squinted at her, then an angel blade was held at my neck.
"Lucifer." I muttered.
"Hello, brother. Fancy a chat?" He zapped me with him.

-Your POV-
A gun to my head, by an arrogant sociopath.
"I'm not a psychopath, you know. " I rolled my eyes.
"Of course not. You are a sociopath." I could feel him smiling at me.
"I'd like to talk to you, but I need it to be private, for obvious reasons." Sherlock looked at me, and I nodded. He motioned for Lestrade to follow him. Lestrade and the Winchesters followed Sherlock out of the building. Lestrade dragged Myla with him.
"Wow. A real Holmes under my control." He stepped up behind me. I could feel his breath on the back of my neck.
"You don't have one. I am not yours to control." He pulled his face beside mine, and he smiled his crazy smile.
"Yes I do. You won't try and stop me, you're not like Sherlock. You, you feel things."  He was whispering into my ear, his lips so close to my skin, that they brushed against it as he spoke. My heart sped up, and I had no clue why. My breathing staggered.
"What are you talking about?" I tried to steady my breathing.
"You want to help me. Don't you? If you don't, then I can only assume one thing. But just imagine it, me and you. A criminal mastermind, and the truly most intelligent mind this planet has ever seen." He had moved his hands to my waist. I had to think. I needed to get out of here.
"No." My voice was challenging. His hands dropped immediately, and he spun me around to look at him. This is all a game to him. So, play.
"Why on earth would I want that?" I kept my tone.
"You're a psychopath! And here I thought you had a shred of humanity." He was teasing. He had his gun ready. Cement floors, can't gain leverage there. The ceiling was mainly pipes. The smaller ones had to be the water and heating ones. The larger one, that was the gas main. Usually these things were under ground, but in buildings like this; they had no choice. Just need to get up there. Get a boost and pull it down. Okay, and go. I kicked Moriarty, and used him as a step. I grabbed the big gas main tube, and pulled myself up. I stepped on top of it, and jumped. I grabbed smaller tubes, and let go. Moriarty was covered in gasoline. I smirked before letting myself get covered in the gasoline, rendering his gun useless. He threw it to the ground.
"That was one of my favorite Westwoods! Gah!Well, until we meet again then." Moriarty jumped out the window, breaking the glass. I ran to the window, and he was nowhere to be seen.
"Damnit!" I screamed. I calmed myself down, and left the room.
"What happened?" Lestrade took off his jacket, and put it over my shoulders.
"He got away. That's what." My tone was frustrated, but monotone.
"Let's get her home and into the shower, before she bursts into flames, alright?" Dean asked, and everyone nodded. We walked to find a taxi on the main street. I lost.