This book has a rakish second-son (Lord Geoffrey) chasing after an aloof and mysterious English heiress (Lady Serena) who has no inclination to marry. But she has a secret - a dark secret - the darkest of secrets - through a contrivance of mistaken identity (as happens a lot to romance types) she's not who she claims to be, but in fact the late Lady Serena's half-sister by an Indian servant woman, brought to England after the death of her immediate family and raised by relatives.
This book gets some points simply for trying to un-white-wash 18th century England through the medium of historical romance. Highlighting the people of color in stereotypically white history is a popular topic in history circles these days, with great efforts like People of Color in European Art History and otherwise trying to undo 300 years of cropping black people out of paintings, so it's pretty natural that this zeitgeist would start hitting the fiction market about this time. I am guessing this book was inspired largely by the 2013 movie Belle, which also stars a woman of color with a British father.
However, the narrative spends far too much time exoticising the main character's appearance, language, and mannerisms to succeed at being a genuine attempt at inclusion in the historical romance genre. While it is more or less normal to spend inordinate amounts of time in romance books describing the appearances of the women, with flashing hazel eyes and cobalt-black hair or whatever, the constant descriptions of Serena's skin color in the usual cliche dark food words began to get pretty uncomfortable after a while, and confusing to boot, as everyone accepts her as white. But you are not for a minute allowed to forget that she is not really British, even though she has lived in the country for years and is considered white. In fact, there is very little of her character to discover in the book, other than her Deep Dark Secret, which is being born to an Indian woman. (Also that she likes sex, because it's a romance book.) She has also decided to forgo marriage because she might have a dark-skinned baby and then everyone will know she is Indian. Basically her character starts and stops at her Indian identity.
As for the romance, it leans heavily on angst to move the narrative forward; the angst, in turn, leans heavily on her secret Indian identity. The conclusion of the book has them being caught by her family while trying to have sex and he is forced to propose while she weeps softly, which was hands down one of the most depressing fictional treatments of the proposal I have ever read. The Happily Ever After is sort of crammed down on you at the end, and the epilogue includes Selena's profound relief at giving birth to a "normal looking" white-skinned baby, even though her family and husband know she is Indian now. Which was something of a perfect ending to the muddled racial treatment I must admit.
This certainly isn't the worst treatment of race in historical fiction, but what with the clear inspiration from modern trends in inclusion in European history, and having read Bradford's books before, I expected something a little more thoughtful.