Here is the plot of Sweetest Little Sin in a nutshell: he's a spy, she is forced into playing at being a spy. The secret they share is that they have been secretly married for eight long years (we learn this in chapter two, so nothing spoiled). Both of them are trying to retrieve a document that lists all of the British operatives before it falls into enemy hands. The person that has that list is having a house party. In order to search the premises of Radleigh's home, Louisa becomes engaged to him (secretly, of course), while Jardine romances Radleigh's naïve sister. Unfortunately, the romance or plot doesn't evolve any further as neither Louisa nor Jardine really talk to one another. Oh, sure, it is explained that their mission is a secret and the fate of the nation is at stake, yada, yada, yada, but to me, it was just forced conflict.
During their mission Louisa and Jardine have quite the little adventure. Neither one of them can make up their minds on how to deal with the mission or with each other. In the midst of this, the ping-ponging began; they were free, they were caught, they got away, they get re-captured, and freed again. Ms. Wells did keep Louisa from being TSTL, however, she didn't do quite as good a job with Jardine. I never understood his motive for marrying Louisa eight years earlier, or his reasons for keeping the marriage secret because I hadn't read either of the author's first two books. When it was finally explained, and vaguely at that, all I could do was roll my eyes at yet another lame, eye-for-an eye revenge plot. Talk about contrivance. To make matters worse, the author gives us not one villain, but three of them. WHY? Yes, it was different, which I am all for, but there was so much intrigue going on that I could barely find the romance in the story. The conflict and resolution was solved rather quickly at the end, which made for a rather unsatisfying HEA.
This was a difficult book for me to get into because Louisa and Jardine have a past that I did not completely understand. Due to events that must have taken place in a previous book(s), I found myself lost for a good portion of the book so that I never connected with either of them. Because they were already in love and married at the start of the book I was cheated out of watching them come to know one another and fall in love. Instead, I was tortured with an entire book of - I must push you away for your own safety but, I can't let you go - type of shilly-shallying that left me feeling empty. I vacillated between liking Jardine and finding him to be a real jerk, enough so that I have no desire to catch up on their backstory. I liked Louisa. tough, she is a strong heroine who does what she has to when her back is against the wall. She is strong enough to fight for the man she loves, and she doesn't whine, or pine, for him when he pushes her away.
Despite not connecting with the main characters and some excessive eye-rolling, Ms. Wells was able to draw me into the story, which is a feat in itself. I enjoyed her last book so much that I was really looking forward to this one, but unless you've read whichever book it is that has Jardine and Louisa as secondary characters, give Sweetest Little Sin a pass.