The Marriage Contract begins when a wealthy twenty seven year old Parisian decides to give up his playboy ways to marry a beautiful Spanish woman. The mother of the girl wants the marriage to insure her daughter will have a luxurious life style as her family fortunes are in decline. I think I see the influence of Samuel Richardson in this, Balzac does refer to him several times in The Human Comedy.
In one chilling chapter the mother gives her daughter advise on how to manipulate her husband to do what ever she wants, with him never being aware. Over the course of the marriage the wife is a serial adulteress but the man sees her as a perfect angel and wrecks his life trying to keep her happy.
I would classify this book as bordering on readable as a stand alone book, not just for those reading through the full comedy.