Can't say I was a fan of the heroine, Maddy. It seemed like every other word was, "I should not....I cannot.....".
Jervaulx is a worldly Duke, who finds himself fighting for his freedom and needing Maddy's help.
It was hard to believe Maddy loved Jervaulx, she seemed more concerned about her fall from grace as a Quaker. There didn't seemed to be much of an examination of her feelings for Jervaulx.
As much as being a Quaker was part of her life so was being a Duchess and all she did was reject her new life instead of seeing how she can compromise the two. There was a constant reason or excuse for her to leave. She didn't fight for her marriage at all, except to say that Jervaulx needed her and that would cause her to stay a little longer. I applauded Lady de Marly when she called Maddy a coward.
As for Jervaulx, there was growth for the character. He recognized and accepted his past misdeeds and sought to correct his mistakes and take responsibility. The reader can sympathize with his frustration and fear of losing his freedom and not being able to command his body to do what he wanted it to do. He had to take strategic actions to save his reputation and keep control of his wealth.
Too bad this reader thought he was fighting that battle alone.