When a "spirit" contacts Lucy Phillips at a séance in nineteenth-century Manhattan, Lucy quickly gains fame as a talented medium who can impart knowledge about the future to wealthy socialites. Lucy is grateful to this "spirit," who communicates with her from beyond, for giving her a life of luxury she’s never known before. By contrast, Lindsay Miller is hospitalized in modern-day New York City for schizophrenia when she starts to hear a girl’s voice in her head.

But when the two girls realize they are really hearing each other’s voices every time they occupy the same physical location, they begin to see possibilities that will change both of their lives forever. . . .