Stanley (Colin Firth), an illusionist, is considered to be the greatest debunker of fake spiritualists. He's asked to investigate a young woman named Sophie (Emma Stone), who has many people convinced that she's a spirit medium. However, some believe she's perpetrating a hoax and swindling her devoted clients.
Stanley gets to know her, but the more time he spends with her, the more mystified he becomes. Unable to uncover any trickery on her part, he begins to question whether she is really psychic.