19 year old Elizabeth Walker moves from England to the US with her twin brother Tyler, escaping her ugly past and least expecting what was coming for her. She is an ordinary girl, well at least that's what she thought. Since moving, she's been having abnormal feelings and odd dreams, especially after her 20th birthday - when Death is at her door. Perplexed, she learns that her existence will change the world for good or bad, that her life will never be the same again, and has to answer the question that's been prodding her since all of her discoveries: What is she?