I sit in the cell. It's blackish-blueish creating a depressing, yet horrifying feeling. My face was covered in dirt, sweat, and blood. My clothes were as badly stained as I was. I could see creatures around, but I couldn't tell what they are. There voices are always muffled, and they sound so far alway. Usually they would tell me that I would be getting out soon, but...when was soon? My clothes are getting to small as I was 2 when they threw me in here, I'm 11 now. They've given me leftovers and they even given warm clothes, but I'm miserable. My only friend is a skeleton that hangs from the wall beside me. It freaked me out at first, but now it brings a strange sense of comfort. Like I have a friend to talk to, even if they don't talk back. Glancing over to the skeleton, I turn toward it. "Hey skeleton. I've heard about how you died. From what I know your family didn't even come to your funeral. Surprisingly, my family doesn't even care about me" I say, lowering my eyes. "Wow, she's truly gone crazy, hasn't she?" The guard outside says to the other one. Then they both laugh, glancing my way. I narrow my eyes, the burning fire inside me bubbling up, begging to be release. I squeeze my eyes shut and I breath in deeply. As if seeing my sudden angry, the guard grins, his yellow teeth standing out in the dark. "Awww, what's wrong with the kitty? Is she getting mad? Want me to call your family? Ha! You don't have any!" The guard bellows, looking back at his partner and amusement. His partner gives his partner a quick chuckle, but glances at me warily. Slowly, I stand up, I'm 5'9, causing me to almost tower over them. My feet touch the smooth floor, barely creating a sound as I move to the bars of the cell. I smile at the guard who laughed at me. "Your funny. Too funny actually. Your not a man, I can tell. You couldn't fight me and win, but I could fight you with both my arms behind me back and win." I say, my lips curling up in a twisted smile, and my eyes challenging his. His eyes flash and he takes a step forward, his partner grips his shoulder, shaking his head. The guard glares at him and continues forward till he stands in front of the cell. The perfect length to attack from. "You are a little girl and I could smash you so don't push me, you little crazy nut." He mutters, danger deep in his voice. I smile, a smile of dead humor that's filled with pain that managed to create sick happiness. I am crazy. I let out a bloody scream, and I reach up to get a grip on the back of his neck. As quick as lightning, I snatch the knife hanging from hid beat and I bury it deep in his neck. The guard behind runs up, but I have the keys in my hand in a matter of seconds. The guard freezes as I smile and jingle the keys in my hand. Fear clouds his eyes and he turns and takes off running, screaming bloody murder. I laugh, a sick and hollow one. Stepping forward, I stick the key in the lock and turn it clockwise till it clicks and flies forward. I pause and look around. Was I really free?, I ask myself. Shutting my eyes, I take a small step forward. Nothing happens, so I take another step forward, and another, till finally I'm out of the cell. A shiver of excitement runs through my body, and I grin. Then I look at the lifeless body of the guard, his shirt had a blood stain on it, but his coat managed to stay clean. Bending down, I roughly pull him out of the coat. Once it's free, I slip it on, it was still warm with the guard's body heat. Silently, I grab the guards legs and drag him into the cell. It takes longer then I thought as he is only dead weight now. Finally, I pull him the rest of the way and I run out. After locking the door of the cell, I turn toward the hallway out of the dungeon. I'm free, I whisper softly, and I walk forward.
Nice story, could use some more descriptiveness, and the part where you say you'd been in there since you were 2 could use a little more description
Background could use more description, as said. Also check your tensest grammar and spelling but those are minor things. Story so far sounds good!