Jo Beverley is a great writer, who's written many excellent books. Devilish, the story of the Marquess of Rothgar and Lady Diana, Countess of Arradale, is one of my all time favorite books and I think Rothgar is one of the most fascinating characters in romantic fiction. All this means I hold Beverley's works to a very high standard and The Secret Duke, while enjoyable, wasn't on a par with her best.
The Secret Duke is the third of a trilogy featuring Ithorne and his cousin Robin, Earl of Huntersdown and his foster brother Christian, Major Lord Grandiston. The books all would have benefitted from more interaction between the three of them because the repartee among the three is always amusing. Rothgar and Diana appear in all three books, but while their role is significant in the first two, giving a real feel for how their life after marriage evolves, their role in this third book is very slight. Even though Robin has married Rothgar's daughter, Ithorne has a problem with Rothgar, mostly it seems because Ithorne, as a duke, out ranks him, but Rothgar has more power. Not very flattering to Ithorne and this potentially very interesting conflict is never played out.
The book starts out well when the heroine, Bella, having escaped from kidnappers and unwisely sought refuge in a waterfront tavern, is cornered by a group of drunken toughs. Ithorne, as his alter ego Captain Rose, rescues Bella only to have her steal his horse and ride off. Captain Rose is a character sure to make any woman salivate, the quintessential pirate figure. From previous books we know that Ithorne as Captain Rose and Robin and Christian as Lt. Sparrowe and Pagan the Pirate have had many adventures at sea on a ship named The Black Swan (all for a good cause of course). I think this is the first book to reveal that there are actually two Captain Roses, the other being Ithorne's illegitimate brother Caleb who resembles him very closely. A few years later, when Bella accidentally learns that her kidnapping was arranged by her brother to pay off gambling debts, she seeks out Captain Rose to help her get revenge and meets with the brother Caleb. Caleb and Ithorne switch places so that Ithorne can find out what's up. Bella becomes aware that there are two Captain Roses and when Ithorne takes her to her home county to look for a way to get revenge, she believes she is with Caleb. Caleb and Ithorne never have a scene together, which I think is a shame. It could have helped illuminate the question of class and identity that runs through the book. Worse, Bella never got on The Black Swan. Why create a delicious pirate like Captain Rose and never take him to sea? This book could have really used some swashbuckling adventure.
After spending a couple of weeks posing as husband and wife in a town near Bella's brother's estate, during which Ithorne and Bella grow ever closer,Ithorne does devise a way to ruin Bella's brother's reputation by exposing his debauched lifestyle. Not particularly heroic, even if effective. Then he and Bella part. This is basically Ithorne's decision. Although there is a period where he longs to win Bella without her knowing he is a rich duke, when they have succeeded in their scheme, Ithorne decides she would not fit in the role of his duchess. Although he supposedly leaves to spare her the unhappiness of being a misfit in his world, it hardly reflects well on him.
Of course Bella gets into another scrape, this one is political, and by hapenstance Ithorne is called on to help. They reunite and you know the rest.
Bottom line, the hero, who seemed so promising in the earlier books, was a disappointment. Bella would have been better off with Caleb. There were many interesting aspects to the book, but none of them were delved into deeply. Theres a definite lack of action or intrigue. There is no detailed description of Georgian life among the elite, which enriched the early books in the Malloren series. King George III appears again, but this time as a man sliping into madness, and the characterization was less convincing than his portrayal in earlier books. Come to think of it there isn't much sex either. But the quality of Beverley's prose is a pleasure to read as always.