Red: A post-apocalyptic re-telling of the Little Red Riding Hood fairy tale. This is the least developed of my concepts and very open to new ideas/contributions.
Kindred: A story centering around the turning of a new vampire and their integration into the masquerade (vampire society and laws). I have thought of multiple ways for this to go: struggling with her own inner nature, comparison between the new experiences of two different newly turned vampires, the comparison of different lives between her and a loved one left behind in the mortal life, or even a comparison of the changing lives between her and some other newly turned creature (werewolf seems so cliche). Open to other ideas, of course. Would control own characters and alternate chapters back and forth between the two different points of view.
Bloody Mary: A murder mystery that needs idea contributors. A serial killer begins taunting and killing off a group of high school students, and one takes it upon herself to try to catch the killer before she becomes the next victim.
Demon Hearts: The concept that someone makes a deal with a demon to extend their life for twenty-one years; at the end of those years, the demon returns to devour their heart. The protagonist has a year left to live, and will stop at nothing to prevent their death. Need more concepts, but also willing to have two characters alternate between chapters.