I have to say, The Ruins would make an excellent horror film. The comparison has been an unavoidable one for me in characters, overall theme, tone, even genre. I struggle to accurately categorize The Ruins in terms of book genres. Is it sci-fi? Fantasy? Horror? None of these properly seem to fit but simply saying "fiction" doesn't do it justice either. So unfortunately I'm stuck with placing it in the category of "survival horror" which I associate far more with films than I do books. 
 The Ruins follows 6 tourists on vacation in and around the Caribbean islands. Friends Amy, Jeff, Stacy and Eric befriend a German man named Mathias along with 3 Greek men, one of whom, named Pablo, decides to stay with them. Earlier in the week, Mathias' brother Henrich abruptly left him to journey to a set of archeological ruins with his new found girlfriend and so the six of them decide to trek upwards to the site of the ruins to bring Henrich back so he and Mathias can go home. Upon finding the location, they become trapped their due to a local village of Mayans blocking their exit and they quickly realize that there is something much more sinister and intelligent about the plantlife surrounding the area. 
 If that sounds like a convoluted set up to get the group of people up to the site of the ruins, it is, and the story drags along until our characters start realizing that something is amiss at the ruins. There is a language barrier between Pablo and the others, as he only speaks Greek and a little Spanish and the four Americans speak barely passable Spanish and no Greek and Mathias speaks English and German. All of this results in needlessly tiring bouts of charades as we try to communicate with Pablo and unfortunately, our understandable protagonists are not much more interesting. Remember how I said that the book in its entirety reminded me of a survival horror film? Part of that came from the characters. Going into a slasher film, one normally does not expect very complex characters, and you're placing internal bets on who is going to end up murdered first. This is how I felt about most of the characters in The Ruins. Even before there is any threat, I found myself frustrated at how short sighted and selfish they were behaving and this carried over once they got trapped at the ruins. Of the six people, the only two I felt any real concern over were Mathias and Jeff. 
 Thankfully, where this book really shines is in the plantlife and ecosystem within the ruins. Mr. Smith did an amazing job building tension and intrigue at what exactly is happening to the characters. He keeps what the plantlife can and cannot do in enough mystery that both the reader and the characters are left wondering if the vines really are as intelligent as they seem, or if the terror brought on by the situation is making the character's imaginations run wild and attribute traits to the vines that aren't actually there. The progressive reveal of the full extent of the potential intelligence of the vines and what abilities they possess is expertly handled, giving our protagonists new senses of hopelessness as yet another challenge emerges. 
 Mr. Smith has a strong grasp on descriptive language, and I found myself rereading passages simply to admire their construction. He frequently would use repetition of specific phrases to help build the rising tension and panic the characters were feeling, even when they themselves weren't thinking or saying anything. He'd also often describe the vines using human like characteristics, which greatly added to the unsettling creepy feel the book had. 
 "She hesitated, slowly, half-turning, and it came to her suddenly that the vine was moving, that this was the sense of constriction she was feeling; it wasn't simply the darkness deepening, the shaft narrowing. No, it was the flowers. Hanging from the ceiling, the walls, rising toward her from the floor, the flowers on the vine were moving, opening and closing like so many tiny mouths." 
 However, in the end the weakness of characters was a major detraction when it came to my enjoyment of the book. The ecosystem itself was full of life, threatening and malevolent and mysterious, and the protagonists seemed so petty and annoying. The tension felt at the scenario can only go so far if I am annoyed that a certain character hasn't died yet because at least that would make him or her stop being so immensely selfish. The ending felt fairly satisfying and had a very timeless feel to it (I do not wish to spoil anything, but it had a sense of hopelessness that I greatly enjoyed) but I wish we had learned more about WHY the ruins are the way they are. Mr. Smith did such a great job building an air of mystery around the ruins and the vines, it was saddening for me to not get any knowledge as to where they came from and why. We hint at possibilities but they have no credence in their claims. 
 The Ruins itself is bigger than the six protagonists we follow, and in that regard the book flourishes marvelously, creating a credible and malevolent threat full of creepy imagery and disturbing ramifications. If only the characters had been a bit more fleshed out and intelligent, this book would have fast been one of my favorites.