SHE [Sirius Black x reader]

The Mission

     I was on my way to Dumbledore's office. He'd called me in after class and with a sinking sensation I was forcing my feet to go up the stairs. 
     "Take a seat, my dear." Dumbledore said as I entered his office. "You must be wondering why I'd asked you to meet me here. I want you to listen to all I have to say before you ask anything."
     "I haven't done anything bad, have I?" I only wanted to make sure. He smiled, shaking his head.
     "Not at all, miss Lupin." He paused for a second. "I need you to do a very important thing for the Order-"
     "Of the Phoenix?" I interrupted, amazed. I then realized that I wasn't supposed to speak until he finished. "Sorry." I added quietly, embarrassed.
     "We need you to join the Death Eaters, so we could have a spy on the inside, to give us all the details regarding their plans." He paused once again, trying to gauge my reaction. I decided I wouldn't give him one. "You shall not announce your brother or any of his friends of this mission. Mister Black will find out everything he needs to know when I'll call him in. I believe that you can confide in the younger Black, as his heart is true and will not betray you. If you have any questions, you may ask them now."
     "When do you need me to join the Death Eaters, sir?"
     "After Christmas Break, miss Lupin." I nodded, standing up and leaving.

     As I entered the Slytherin Common Room, I found Regulus standing on couch, reading a book.
     "Reg, do you mind coming with me?" He shook his head, immediately standing up.
     As soon as we entered my room, we sat on my bed. I fumbled with my hands.
     "Dumbledore wants me to join the Death Eaters." I blurted out. Regulus' eyes widened, trying to tell if I was pulling his leg or not. "For real." I added, seeing the uncertainty in his eyes.
     "And what do you want?" I shrugged, avoiding his gaze. I haven't actually thought about what I wanted.
     "To be useful."
     "I hope you know how dangerous it is." I nodded, finally looking back at him.
     "I know, but I have you." My words made him smile.
     "Have you told Sirius yet?"
     "Dumbledore said that I can't tell anyone else, except from you." Regulus raised his eyebrow cockily. "He said that he was going to tell Sirius, but Remus or anyone else couldn't ever know." My best friend nodded.
     "Take care of yourself, Y/n."

Author's Note: What a fun plot twist!! Hope you enjoyed this part!!