A fine, good Heyer's Regency novel. One of shorter. One of her last and I could have seen her professional pen here. One may say: Good job. 
 Yes, I have noticed many similarities with her other stories, e.g. 'The Foundling', but it didn't bother me because I found here engaging characters (Simon was like some splendid heroes from her other romances, Lady and Lord Wroxton had an interesting own story I am sure) and so beloved Heyer's language/dialogues. 
 In my opinion, this book had also something important to tell. Reading it I was thinking about 'charity girls'. All those girls/women of those times. Girls which hadn't the meaning. As a rule, women had less possibilities than today, but 'charity girls' had even less. I suspect, that many of them would have had better (happier) life if they had lowered their status (getting married with a farmer or a clerk or even working some lighter physical work). But they were slaves of their class. 
 So, because it was good written (with a deeper level), pure Heyer and I have a nice time - I am giving it 4 stars. 
 But I have to admit it hadn't a spark. This spark which made some of Heyer's stories simply marvelous, genial. For example: an adventure in The Foundling, Dominic in Devil's Cub, banter in Faro's Daughter, Sophy in The Grand Sophy. This sparkle, which makes that I want to read it again, even before I finish the book.