Confusing in a way: decent wealthy powerful marquess seemingly-randomly proposes to someone he seemingly hardly knows before start of book so we don't know the whole story, just gossip about it; that woman (sister of heroine) becomes ruder and more encouraging of men to stalk her sister to try to get the sister married even though sister has no urges or complaints about being single at age 18 or so and although the main dude she encourages kidnapped his first wife for her money and is clearly Bad News whom the woman protagonist dislikes; nice woman protagonist gets dumber and more hostile as time goes on; and I kept expecting there to be a big plot or reason why for all of this. Yes, I know it was traditional for the elder sister to marry first, but she had barely had a season or two, and as the big explanation-gossip in the beginning says, it is unlikely parents would turn down serious wealthy titled handsome dude just because older sister is not yet married and doesn't care about it and isn't making any fuss about it and isn't 'past her last prayers', as they used to unkindly term women 'too old' to marry: early 20s and later.
spoiler about ending and motivations
Nah, there was no big masterful plot. There were just dumb and contrived reasons. That part was disappointing. I kept expecting it to be that someone, probably the marquess, who was presented as intelligent and powerful, had contrived something that looked on the surface jerky but was really deep and secret plotting, but nope--eh, I've read worse, but it's discouraging to have the prots turn out much dumber and more foolish than the book had lead the reader to expect.