Duncan Campbell, a young Scotsman, is burdened by “second sight,” a hereditary gift manifesting as a terrifying auditory omen of a horse with a dangling shoe. Seeking a reprieve from these supernatural afflictions, he accepts a tutoring position at Hilton Hall in northern England. There, he becomes fascinated by the daughter of the house, a woman whose waking life is defined by a strange mental vacancy, but who possesses a profound and hidden soul while in a state of somnambulism. As Duncan attempts to bridge the gap between her two identities, he realizes that his ancestral legacy may have followed him across the border.