Lauren Edgeworth had retired from Society after her aborted wedding. (See One Night For Love for the details). She has been living quietly as a companion to her cousin and good friend, Elizabeth, Duchess of Portfrey. Lauren has been understandably soured on marriage and would like to establish her own home somewhere - Bath would be nice - and live a quiet life.
Kit Butler, Viscount Ravensberg is a rake and a rogue - all Society says so. Lauren's first glimpse of him is when he is stripped to the waist, and brawling in the park with three low class toughs. The three had been trying to forcibly kiss a milkmaid, and Kit was out to defend her honor. Lauren is horrified. She is even more horrified when Kit shows up at the ball that her friends have persuaded her to attend. Kit is all charm and courtliness. He waltzes with Lauren and against her will she finds herself much taken with him.
Kit meets Lauren at every opportunity he can, and asks her to marry him. He is honest with her, and explains that his friends are sure a lady like Lauren will never marry a rake like him, but he needs a bride. His family is after him to marry and have even chosen a bride for him, so he would like Lauren to pose as his betrothed (and then jilt him) to get his family off his back. Lauren agrees. By jilting Kit (and because of her previously aborted wedding), she will be rendered unmarriageable, which will allow her to retire to that quiet life in Bath she wants. But she makes Kit promise that for the time she spends as his fiancée, he will give her a summer to remember.