Stumbling out of bed, Luna didn't even flinch as her feet hit the floor despite knowing that the floor was probably icy with the wintery chill that had always managed to fill her room. It didn't matter, because she couldn't feel it. It felt the same temperature as her own skin, nearly warm to the touch.
"Luna?"
She flinched, diving back under the cold blankets just in time to see the door opening, shedding dull florescent light that was still far too bright for the room she was in. Heavy curtains covered the windows, not allowing any hint of sunlight into the room.
"Are you still feeling sick?"
The only response Luna was willing to give was the shake of her head. She heard her father sigh and the click of the closed door, wishing her eyes could form the tears of loss she felt for a person she had yet to lose, a person who didn't know they had already lost her.
The fluorescent light told her that it was night, regretfully Luna left her bed once more, fully dressed. She took a moment to glance around her room once more, half-faded memories returning to the back of her eye. Luna had to stop those memories prematurely, or she would never manage to go through with what she planned to do.
Luna was a danger to everyone around her at that moment, and perhaps for as long as she continued existing this way. She didn't know how it would end, only that it would someday. Luna didn't know when or how, but she knew she would never be able to do that to herself.
Pulling the curtains aside, Luna opened the window and took her first breath of fresh air in nearly a week. It had taken her a week to decide and plan this, but it would take only a moment for everything to be undone. She couldn't let her father find out until she was long gone, especially with the hunger than gnawed at her stomach like acid.
A quick glance back and Luna threw herself out the window, knowing she would never do that if she had truly thought about it. The landing was jarring and awkward, if she were human Luna knew she would have broken at least one bone but she wasn't. Not anymore.
With just the clothes on her aback, Luna ran as fast as her legs could carry her. A surprising speed if she could bother to really think about it, but she couldn't. Luna could only think about the man, her father, who she had left behind. He was a widower that had lost his child as well as his wife in a span of five years.
He would live on, though, he had to. There would be sadness in his heart, but that would be a far cry better than the stillness that had enveloped her mother already. That was one memory that had not faded with time, and Luna did not want to have a similar one of her father in the near future.
That was the whole point of leaving. Luna knew that her hunger was going to fill her mind, clearing any thoughts otherwise and the closest living being to her would have been her father. It had always been her father.
So she ran, eyes turning red from the exertion and thoughts turning more and more disjointed with every mile that passed. It was like going to sleep, except her body was still moving and on high alert.
Luna didn't notice when she happened upon a sleeping body in a darkened alley, nor when the screams started. The blood that filled her throat was like nothing she had ever tasted before, giving her more energy than Luna could ever remember having.
As her mind returned to her, Luna could only feel a dull sense of horror as she stared at her bloodied hands and clothing. She had expected something similar, and was grateful that it wasn't her father, but she hated what she had done.
Luna hated that she had lost her humanity.
Written for Defence Against the Dark Arts: write about a character who has been contaminated with either Lycanthropy or Vampirism