In Faro's Daughter, Max Ravenscar has been enlisted by his aunt to defer his cousin's attention from a young lady from a gaming house, who she believes is a fortune hunter. Deborah Grantham is a young lady who is trying to help her aunt and herself rise up in society and away from the gaming house that her aunt owns.
Deborah has no intention of marrying Ravenscar's young cousin, but Ravenscar unaware of this, offers to buy her off, to which she sees as an insult. She vows to torture him at every possible moment, by making him believe that she fully intends to marry his cousin. Of course, these small bits of annoyances soon escalate. Hilarity ensues, and it wouldn't be a Heyer novel without some big misunderstandings.
Faro's Daughter had one particularly hilarious scene, which I won't spoil for those of you who haven't read it, but the dialogue had me cracking up. This was another delightful, hilarious Heyer romance.