What kind of whack-job government requires sixteen year-old girls to get proof-of-age tats on their wrists that publicly announce they are ripe for the raping? How does a society even get to that point? 
 To be fair, the synopsis warned me, but bravo to the author for managing to make my skin crawl anyway. 
 Ug, and crawl it did, right from the beginning. Sixteen year-old girls have zero rights in the year 2150. Men openly leer at young girls and check out their wrists to see if they are legally available. If an of-age girl is preyed upon, there basically is no legal recourse for her to take. She is 16 or 'sex-teen' as the Media so cutely describes her, and was of victim of her own poor choices. However, this is only one aspect of the future world that Julia Karr sets up for us. Another defining point is a tiered level of citizenship, where being at level one makes you only a step above being homeless and being a level 10 gives you a cushy job and nice play to live. How you are treated by hospitals, the Media, and your peers is determined by your level. Other futuristic elements include hovering ttransportation vehicles, or 'trannies'; points, which are used to buy food and goods rather than cash; ID chips, which citizens have implanted in their hands; and GPS tracking implants, which everyone has in an ear until age 16. 
 Karr does a great job of making this world plausible in her book, and that might have a lot to do with her characters. Nina is believable from the beginning as care-taker of her physically abused mother and loving older sister to Dee. Aside from her mother's horrible boyfriend, what she is stressed most about is turning 16. Her best friend, Sandy, is the boy-crazed ditz we all would love to smack (honestly, I don't think I could take a real life Sandy). Derek is a passionate musician with a mellow attitude, and Mike simply is a likable guy who isn't a threat to anyone. Add in new friend Wei (who is freaking rad, tough and very artistic) and love interest Sal, and you've got yourself a believable high school group of friends. 
 This was a decent book with an interesting premise. However, my mind did wonder a few times, but the chapters were short and the story would quickly pick up again. I think XVI probably could've been a shorter, more tightly written book. It seems to have two major plots for Nina: 1) making sure she and her sister are safe (there are significant threats to them both); and 2) completing the final task her mother left her before she dies after being lethally attacked. Besides that, there were many subplots, mostly to do with the drama one would expect within a high school crowd. They seemed to mesh together relatively well and one flowed in and out of another, but at times it was a little difficult sorting through what was important. The all-controlling government and Media invoked a sense of paranoia, but this wasn't an overstretched aspect of the story; it simply was something the characters dealt with through a few different means. Obviously, sex is a major topic in the book, and it was interesting to see how control over it could shape a one's entire sense-of-self. It is portrayed by different people as a choice, a commodity, a right-of-passage, a means to a better future and, of course, as rape. There are never graphic, detailed descriptions of sex or rape, although the few occurrences of leering men and the references to rape will make you cringe. I don't think it was overly done, however, and it really does make you aware of how it must be for Nina and other girls who have to live this way. Given the synopsis, the reader is fairly warned. Thankfully, Nina is a particularly self-aware character who was raised by a mother determined to make sure Nina was as free from sexual threats as possible once she turned 16. However, Nina fears men and sex regardless, and her views on her own choices are heavily influenced by her mother's relationship with her violent, disgusting, foul miscreant of a boyfriend. Seeing her work through these fears is one of the more significant subplots of the book. 
 XVI had a lot of interesting elements going for it, but it also left some things unexplained. I would've loved having more background on the following: 
 ***It's never explained how or why the U.S. disintegrated and/or was overtaken. Several different groups seemed to have had control between now and when the book takes place, but I could have used some more concrete background information. I am one of those people who needs the narrative of the past to help me define the present. 
 ***Why the 10-tier system? That's a whole lot of tiers and some big time micro-managing. I would've have liked to know what defined the different tiers. We do learn that occupation defines status to a certain extent, but so does whom one marries. 
 ***Although girls get tattooed at 16, boys don't until 18. I definitely did not get the impression that this was the green light to adult women that the lads could be carnally feasted upon, so I am not sure of the significance. 
 ***More on the NonCons (which I assume means 'non-conformists' - duh). How did the resistance start? What do they do to combat the government? It seems to be more a group of people who simply live under the radar, but there is little concrete action taken by them in the book. 
 XVI ends on an interesting, hopeful note. However, I still wanted answers to my questions and visited Karr's website to see if I could find any there. It turns out that she currently is writing a sequel called The Sisterhood, which I look forward to reading, especially if it contains more of Wei and gives additional background to XVI. Although the writing could have been tighter, this was a decent debut by a new YA voice. You have to have a stomach for the issues it deals with, but for those who do, I think this will be an interesting read. Karr wrote believable characters, an easily imaginable setting, and an interesting plot. For me, these are the most important things in a story, and I likely will be back to see what happens to Nina & Co.