Dancing In the Darkness

After witnessing her parents' brutal murder, Rosie Simon finds herself as a subject of S.H.I.E.L.D. Terrorists and dark forces are after her, and a poison inside her body is slowly making its way to her heart. She has secrets yet to uncover, and the Avengers ready to kill her or accept her at any moment. (Sorry, I'm bad with summaries...) Eventual OCxSomeone. M for future themes!