When Philip and Marie Deflorette are unable to return to the United States after the Civil War because they had served as agents of the Confederacy, they try to climb into the upper ranks of English high society. An introduction to Lord Lytton, a statesman and bestselling novelist, lands Philip a job and gives Marie an opportunity to pursue her dream of becoming a composer. But when Philip receives a note threatening death if they do not leave England, he wants to return at once to America. But Marie, unaware of the threat, insists on accepting Lytton’s invitation to spend a week, along with other invited guests, at his country home, Knebworth House. There, amidst the splendor of a centuries’ old mansion, adorned with spires and gargoyles, and surrounded by beautiful parks and gardens, the Deforettes will also find that danger lurks all about them.