This was just a fun story with Heyer's trademarks shatter throughout. Because it's been awhile since I read Heyer it took me a few chapters to get back into her style of writing. This of course cleared up once I got into the story.
Frederica came across as a strong and devoted sister to her young siblings that drag her along with the Marquis of Alverstoke into many scarps that end up funny or a little to close for comfort. Alverstoke is aristocratic bored jaded man, and his change it adorable as he not only falls slowly in love with Frederica but starts to truly care for her younger brothers breaking him out out his lifetime boredom.
Not only is the story and characters a delight, but the history of new mechanical engineering at the time was fascinating.
I just wished Frederica and Alverstoke has more time as lovers then it coming at the very end. Still Heyer brought charm and history in this heartwarming story that was just a plain joy from start to finish.