The Demon’s Mistress is a novella. In my opinion, novellas are the teenagers of literary work too short to be a well rounded, mature novel and too gangly to be a sweet, cute short story; it’s hard to find a good one; they don’t get a lot of love. The Demon’s Mistress is part of a romance collection. We all know how that works, there’s one known writer and two or three less known writers and one of them is basically unreadable, one is okay, and one is surprisingly good. The Demon's Mistress, despite the awkward length and truncated plot, would be the good one.
The Demon is Lord Vandeimen, who has returned from the Napoleonic Wars to find his father dead and himself penniless. He is in the process of killing himself when he is interrupted by Maria Celestin, the titular Demon's Mistress. She has tracked down Lord Vandeimen to ask him to pretend to be her fiancé to keep the fortune hunters away during the season. Obviously, that's not the real reason she approached him, and despite being suicidal, he's suspicious as well. On the other hand, he doesn't have a lot to lose, so he agrees to help her. It turns out that she really sought him out because she found out that her late husband swindled the late Lord Vandeimen out of a large sum of money. Now she is trying to give it back and undo the wrong. After assessing Lord Vandeimen's state of mind, Maria Celestin thinks that he would either refuse or waste the money if she just gave it to him, so she is using it as a lever to bring him back to productive life.
The upshot of all this is that the two spend a lot of time together, with Lord Vandeimen romancing Maria Celestin, and naturally they fall in love. There are some complications, including her explaining what her late husband did to his family, and thank God for lack of space, because Lord Vandeimen sensibly decides that it wasn't her fault that her husband was a jerk. The real problem is that Maria Celestin is eight years older than Lord Vandeimen. Because of the age difference, she shunned by her close friends who believe she's robbing the cradle, and, more than anything else, she believes that she is too old to be able to give him an heir. She wastes a lot of time trying to talk him out of marriage, but, in the end, they have their happily ever after.
Overall, it was a good novella. The biggest problem is that it would have been much better as a full length novel. There’s not a lot of time to develop the relationship, especially the changes in Lord Vandeimen, so everything feels rushed and forced. I think the author was working with too much stuff to fit into a novella and do the story justice. (And I’m not even going into her preference, and attendant shame, of being sexually dominated and that his childhood friends hate her because of her late husband’s nefarious business practices.) The minor complaint I have, and it is petty, is Lord Vandeimen is always described as having primrose colored hair. I’m sure this is evocative for everyone but me. I looked up primroses and found out that they come in pink, yellow, cream, blue, and red. I’m guessing that she meant that he had red or creamy white hair, but I’m going to picture him as having blue.