Sable Martin's float upward from farm lass to wife of an 18th-century M.P. is as steady and predictable as a bubble in molasses. Aided by a kindly itinerant preacher, Sable is taken on as companion to elderly Lady Agatha who adores her. But Lady Agatha's greedy niece, suspecting Sable of shooting for an inheritance, drives her off. She is rescued by cool, apparently callous Tom, an M.P. and brother of profligate Morgan, by whom Sable conceives a child. Before the birth, Sable will play a part in freeing a black man from slavery, investigate a brothel procurement racket, and marry Tom, whom she will come to love. It all ends with Sable beginning to win over the toffs and inviting Mum to tea in the manse. From hut to Hall--a passable back-portico entertainment.