An aristocratic Englishwoman who is bitterly opposed to the American civil war, her husband who is a fanatical Confederate officer, and a freed Negro slave who is an overseer on their Southern plantation are lured into a bizarre scheme to save the Confederacy from defeat during the war.
Her husband is enthusiastic about the scheme but she doubts if it is genuine, and so does the Negro, but no-one takes any notice of him because of his inferior social status.
They are lured into the scheme by a mysterious visitor who claims to be a Confederate officer.
But he has a slight British accent.
Is he really what he claims to be, or is he a British secret agent?
When she hesitates to agree to the scheme he unleashes a series of terrifying events in an attempt to persuade her.