I guess this could be a 3.5 and I hate to rate it low, but it's just not up to the standard set by the previous three.
Hart and Eleanor are great characters and I love their chemistry. She's his first love, pretty much his only love, and if he hadn't blown it during their first engagement, he'd have been married to her long ago.
Eleanor is the impoverished daughter of a flighty earl. She comes to Hart with an offer to help him if he'll hire her. She not only needs the money, she's in possession of something that could hurt him horribly. Someone has decided to send her incriminating material regarding Hart and she wants to protect him. That's just her way, but she still cares deeply for him.
There is a lot to like in this story. There are also things that just lay there. For example, why keep telling us about his "dark sex games" and then make it all just go away. If it's an issue, it's an issue. Either we have to see what it is and that Eleanor accepts it or we need some detail to know if we
accept it. Ultimately that part came out rather timid and vanilla.
I mention the "dark sex games" because we actually do know they exist with Hart. In "The Madness of Lord Ian MacKenzie" we find out that he applies "erotic asphyxiation" to women from time to time. That's some serious business there, but that level of "darkness" doesn't exist in this story. Not that I want to see it in action or anything like that, it's just that if it's brought up, it ought to be resolved in a manner fitting the level of importance implied.
I'm not going to get into spoilers. I just felt like there were missed opportunities and a bit of smoothing over of rough edges and that was disappointing.
Ian plays a big role in this story and that is always a plus. I just love that character so much.
There are some laughs, and some really heart-wrenching scenes, and it's definitely worth reading. I just think it's also the weakest of the series.