I wanted to like this so much, because two of my sisters absolutely loved it, but too many aspects of this book just fell flat for me. Just shows how reading tastes differ ...
Setting: The exact date is not stated, but it is almost immediately after the Civil War ends. One of the characters is from Virginia (and is there in the prologue, but leaves soon after), and the beginning of the story is set in Chicago (where the other character hails). Most of the book, however, is set on a train that travels from Chicago to New Orleans. It is not clear at any given time where the train is; only the names of the stations are mentioned. Though the greater location doesn't garner much focus, the more specific setting does: the train. There are plenty of descriptions of the train cars, where everything is, and the possibilities (and impossibilities) regarding stealing the valuables. The post-Civil War (thankfully, the characters never called it that) year also heavily influences both characters' actions, perspectives, and experiences. The hostility in the North toward the Southerners is shown very well.
Characters: As the perfect southern gentleman who is now often moody because of his war experience, Ridge is quite an endearing hero. He's exceptionally quiet, but that fierce fighting spirit explodes at the best times. I really wish his character arc was shown more, because his spiritual growth was only mentioned after the fact, and I never clearly discovered why he was so attracted to Laurel--especially after he found our her darkest, dirty secret.
Laurel is quite annoying, and I hate to say that I didn't grow to like her throughout the book. She is rude, annoying, pushy, selfish, and her motivations weren't clear to me (my sister later explained her reason for pursuing Claude, and it does make sense). Her "ignorance" on why she has seemingly unexplainable feelings for Ridge got on my nerves; like, you've never had a crush before? Since obviously it is only that, at the beginning. Also, jealousy at a mention of someone else's *possible* (and usually not in reality) beau (or female version) grates on my nerves, especially when the jealous person doesn't realize they're jealous because they like the other person. And yet it's this mysterious fact of life that people have these irrational jealousies, and we can never figure out why. Laurel's character arc is a little choppy, too, I thought. Her spiritual journey seems to follow badly.
The other characters are done pretty well. Claude, especially, has a good role, and Aiken and Lucas are also good additions. I was a little disappointed that the bad guys are revealed so early (instead of the reader finding out with Laurel), but there is an element of the mystery that isn't understood until later.
Plot: The plot is good, unique, and done well. Like I said, the mystery is revealed to the reader a little too early in my opinion, but there remains a level of suspense. I feel like some parts were tied up a little too neatly--all because of Laurel's smart, forward thinking--but I get you can't have everything turn out the worst possible way (actually, I think it would be improved if these smart actions are done when the reader has Laurel's POV). The beginning of the story drags somewhat during a scene/conundrum that isn't solved immediately, but is solved eventually with the first solution. In addition, I think the plot faltered a bit due to the writing, especially when it followed Laurel's thinking. I can't really put my finger on it, but for some reason I couldn't be engrossed in the story and the information. I never really got into Laurel's head--I only heard her dialogue, which was kind of stilted and didn't really give a good sense of her thought process.
Romance: I think this is where the rating faltered, because reading romance is what I like. I felt that the author just assumed that "of course they're attracted to each other, because they're the hero and heroine", without giving any real reason for it. Too much was forced down my throat, and I didn't appreciate it. All that hate and animosity between Laurel and Ridge, and a life-threatening situation fixes it all. Actually, that's not even accurate. Everything is fine before that, but they haven't talked yet.
Faith content: It is present, and the conclusions are good, if their pathways aren't so smooth. In the beginning, Laurel's Christian family is portrayed as bad, but a little thought on the reader's part will tell the reader that the unpleasantness is from Laurel's perspective (but she never does realize that they are not unpleasant). I thought Laurel's final perspective on her Pinkerton work during the War was interesting, and merits discussion. But Laurel couldn't really have that discussion in the book, because her actions couldn't be defended.
If I add anything else, it's that all of my opinions are totally subjective, because this is one of my sister's favorite books of all time. If you're not bothered by any of my aforementioned pet peeves, and you enjoy 1800s mystery aboard trains, I would recommend it.