In 1944 Spain young Ofelia (Ivana Baquero) and her ailing mother (Ariadna Gil) arrive at the post of her mother's new husband (Sergi López), a sadistic army officer who is trying to quell a guerrilla uprising. While exploring an ancient maze, Ofelia encounters the faun Pan (Doug Jones), who tells her that she is a legendary lost princess and must complete three dangerous tasks in order to claim immortality.