Olivia Lytton is caught between two men, both suffering from serious psychological problems.
She was betrothed as a child to Rupert, Marquess of Montsurrey, who was severely injured during his traumatic birth, leaving him with the intellect of a charming and earnest 11 year old boy. Rupert has been drilled to present an adult appearance, writes poetry, and volunteers for the British army, but marriage to him will compel Olivia to function as his caregiver and estate administrator.
Her secret love, Tarquin, Duke of Sconce, is a handsome, brilliant mathematician, who has already lost one wife and a child due to his inability to read other peoples' emotions correctly, predict their emotional reactions accurately or express his own emotions. An isolated mathematical genius with almost no friends, Tarquin's life is managed for him by his overbearing widowed mother, who wants to marry him off to Olivia's extremely proper bluestocking sister.
An alert modern reader will quickly grasp that Olivia is facing a lifetime coping with either an intellectually disabled spouse or a spouse with Asperger's Syndrome.
Olivia herself is atypical of Regency heroines, describing herself as fat, loud and fond of risque jokes. Not your standard Regency romance novel lead characters, to put it mildly. Part of the allure of the novel is wondering how the author can produce a HEA ending from these unpromising elements.
Despite the tough medical problems of the male leads, the plot is surprisingly humorous and filled with genuinely romantic sexual episodes. If you are interested in a Regency romance that takes parts of the genre's conventions and stands them on their heads, you'll like this novel.
I gave it four stars instead of five stars because I felt that the novel took too many liberties -- during the last third of the book -- with the actual history of the Napoleonic wars and the British army's real life behavior. But if you are not a strict history buff, such liberties will not be a problem.
I am now rereading the novel, after a first reading where I rushed through it. I am savoring it at leisure.