Elizabeth Masterson (Reese Witherspoon), a young emergency medicine physician whose work is her whole life, is seriously injured in a car accident while on her way to a blind date. Three months later, David Abbott (Mark Ruffalo), a landscape architect recovering from the death of his wife, moves into the apartment that had been Elizabeth's. She begins to appear to him. However with ghostly properties and abilities it is clear something is not normal, she can suddenly appear and disappear, move through walls, and once takes over his actions.