SPOILERS AHEAD.I MEAN IT. I GIVE AWAY THE ENDING...
I wanted something fluffy to read while editing my magic pirate book and Cotillion seemed like just the job. Kitty Charing has been raised by her irascible adopted uncle. Determined that he is dying of gout he summons Kitty's unwed male cousins-by-adoption and promises to leave his considerable fortune to whichever one of them will marry her, leaving nothing to Kitty in her own right. None of the cousins actually needs the money, being reasonably well-heeled. There's Hugh, a stiff and slightly pompous clergyman; Freddy, an empty-headed dandy more concerned about the knot in his neckcloth than acquiring a wife; Dolphinton, an Earl, but slow-witted, and Jack, a regular Corinthian, gamester and rake-about-town. It's Kitty's choice, but the one she really wants, bad-boy Jack is the only one who doesn't respond to his uncle's summons. So Kitty comes up with a scheme to get herself away from Uncle's restrictive country home, up to London, made fashionable, and introduced into society, to put herself in Jack's way. To this end she coerces the amiable Freddy to a sham engagement, is installed with his respectable married sister (whose diplomat husband is abroad) and is launched upon society. She enters into several matchmaking schemes for other people, but neglects to make progress with her own. The dashing Jack proves to be not all Kitty believed him to be and in the end it's dear, dependable, thoughtful Freddy who comes through, not quite as empty-headed as he thinks himself.