A respectable young widow and mother of two children, the Marquise of O- finds herself inexplicably pregnant after being rescued by a Russian officer from the attentions of his soldiers during the storming of her town's citadel. Convinced of her own innocence and wishing to vindicate her own integrity, the Marquise places an advert in the newspapers, appealing for the father to come forward and promising to marry him. But will this be enough to quench her family's doubts and the derision of the society around her? Will this help her solve the mystery and urge the perpetrator...