As a child in 1906, Arne Horsfall finds a sealed crate, addressed to a professor at a local college, that has fallen off a train. His father stores the object in the barn until the wayward professor can pick it up. But the crate operates like a Pandora's box on Arne and his mother; overcome with curiosity, they pry it open and unleash an evil spirit. Physically, the spirit looks like a mummified dark-skinned man--not, however, like a black man--and his mother recognizes it from the stories of her childhood as one of the huldufolk , the "unwashed children of Cain," evil and immortal. When the spirit awakens and escapes, the Horsfall farm becomes blighted; Arne's father dies of gangrene at its touch, and his mother becomes its slave. At this point the novel flashes forward to 1970: Arne is a deaf-mute in a mental institution, where he has lived for untold years. His art therapist, Enid Waller, takes pity on him and invites him to her home for dinner. Out of the hospital for the first time in decades, Arne senses the dark spirit, who has multiplied and stirs now in response to Arne's freedom. The lives of the Waller sisters will never be the same.