A totally madcap crazy story that you have to read with your tongue firmly in your cheek - there's a pretend highwayman, a real highwayman, a truly wild orgy, a damsel in distress who is rescued by a duke and his loyal sidekick, a good-hearted whore, at least 3 curricle chases (the Regency equivalent of a car chase, I guess), a last-minute rescue from a horrible fate, i.e. marriage to a cold-hearted society lady, and on and on. St. Raven and Cressida are wonderful characters, though, and their interaction is a joy to read.
One of the things Beverley does very skillfully is to build up the suspense around the possibility of the heroine's reputation being "ruined" for actions that in this day and age wouldn't merit even a moment's attention. Much of the plot is taken up with making sure, by whatever means possible, legal or otherwise, that Cressida's reputation remains unsullied, and the reader is sucked right into caring and worrying about this almost as much as the characters in the book do!