The species z10-99 have only been witnessed a few times before, they age quickly before they mature, and seem to stop as they get older. 'Ruby' as a nurse calls her, is one they have managed to tame. She has never brought death upon someone, even though her kind thrive on it. They preform all types of experiments on her, trying to figure her kind out. All goes well until the nurse Ruby has grown to love, passes away due to age. Soon after, Ruby experiences the joys that come too her kind after killing a human. Will she ever be stopped? Or did humanity have this coming..?