A/N: Written for the Hogwarts Online February Challenge: Missing Moments. I chose "Ginny making her way into the Chamber of Secrets"

Monster Inside Me

I'm stuck inside my own head, screaming and fighting and begging, down on my knees, begging him to let me out. He won't, though. He never does. Never. He just yells at me to shut up, then forces me even further back into the tiny alcove I've hollowed out inside my mind. It's the worst feeling in the world, because whilst I'm stuck here, I know exactly what to do, how to stop him taking control the next time; but when next time rolls around, I can't remember a thing. Nothing except the searing, burning pain that wraps around each muscle and tendon and ligament like icy fire. I can't break free, no matter what.

He forces me out of my soft, warm bed and down the chipped stone steps into the Common Room. I feel myself consumed by him, by his insatiable hunger for Harry Potter. It takes me over, until I can barely remember why I need to fight him. Why should I fight him; I am him, and he is me. Harry is only a nuisance to be eliminated, a tiny boy to destroy, as he should have been twelve years ago.

But a tiny, inconsequential part of me remains, and remembers that I love him. It keeps me vaguely me as Tom walks towards Myrtle's toilet wearing my body like a glove, a spark of determination lighting my eyes.

He pushes open the door with my hand, and I stare at it for a moment, seeming to see something move and strain under my skin. We're fighting so hard for control that my body can't take it and fights back too.

He hisses, and it's with his voice, not mine. He cracks my neck bones and glares at me – him – us in the mirror until I back down. I know I can't fight him, not really. He's too strong, or I'm too weak. I'm really not sure anymore.

I feel him drag my fingers over the frigid metal of the taps, seeking the tiny engraved serpent I've felt so many times before. Then a strangled hiss sounds from my throat, echoing dully around the empty room, a noise that's so familiar now, but that I don't understand. I only understand the effects of us uttering it: an increase in the intensity of the fire that curls itself through every pore of my body like smoke, and a grating noise that screams in my ears as the sink slides away, exposing the entrance to the chamber. The Chamber of Secrets lies beneath our feet and its malodourous stench rises into the room until I have to struggle not to gag. He wouldn't look kindly on that.

We slip inside the passageway, deep beneath the castle and slide down, down, down, until it feel as though we must have reached the very centre of the earth. Only instead of being hot, it's cold, so very, very cold. I try to shiver, but he stops me. He despises any form of weakness at all. We're just the same in that respect, only he thinks the things that make us strong are our weaknesses. He hates any show of emotion, thinking that this only gives someone the power to hurt us. He's right, I suppose, but also so very wrong. But he'll never understand that – for Tom Riddle, power is the only thing that matters.

I muster my strength for what I know must be a final attack. We're nearly at the chamber, and then it will be all over. I know I'm going to die here, all alone in a filthy pit, with stagnant water in every hollow and dirt and slime coating every wall until they glisten dully in the greenish, subterranean light. If I'm going to die, though, I may as well go down fighting.

I push with all my might against the thin membrane that separates me from him, willing myself to break through and regain control over myself. If I can do that, even for just a minute, I might not die in vain. I might, just, be able to help Harry, help everyone.

As I push, the memories come flooding back. The red paint, daubed on the walls. The chickens I killed, their feathers stuck to my uniform, almost giving me away. The cat. Colin. Hermione. Penelope. Oh, God. Penelope. How would Percy ever forgive me? Maybe I deserve to die; I tried to kill by brother's girlfriend. And now I'm going to help him kill my brother's best friend. I don't deserve to live, I don't deserve their help. My resolve weakens, and I stop fighting, subdued now. He takes advantage, and springs, pressing me firmly back into the recesses of my mind. I'm too weak to resist.

And then I'm suddenly free, a weight torn from my shoulders as I flood back into the ripped and damaged caverns of my brain. I've been under his control for too long though, and I can barely support myself. I stumble, my shoulder hitting the solid stone of the floor with a thud and a crack. My eyelids flutter, one last time, and the last thing I see is the smiling face of Tom Riddle, his black eyes boring into me as I close my eyes for the final time.