This is an excellent book. Rick Yancey, author of the Printz-Honor winning Monstrumologist series and The Extraordinary Adventures of Alfred Kropp, has delivered a remarkable tale that manages to revitalize the idea of an alien invasion, in which the aliens are brutally efficient without ever apparently leaving their space ship in orbit around the Earth. Thanks to the constant paranoia, the knowledge that no one can be trusted, this book is terrifying on a level that few other novels aimed at teenagers are able to be. Although, admittedly, this book does not have any truly original ideas, all the elements it takes from other novels are pieced together in a way that makes them uniquely its own, and the characters are so strong that you do not care about any derivative tendencies.
You could argue that Cassie is a carbon copy of Katniss from The Hunger Games, what with her protectiveness of her younger brother, her toughness, and her uncaring, unfeeling exterior that hides her vulnerabilities. But, in my opinion, she is an even stronger character than Katniss is, because the book also shows through a series of flashbacks in the first hundred pages or so how the waves forced Cassie to change from your average teen girl who frets over her hair and has had a crush on the school jock since third grade to the tough survivalist she is now. This extra dimension adds a certain accessibility to her character on a level that Katniss never had. And although she is easily the most developed character in The Fifth Wave, all the others are fascinating in their own right.
The plot, also, is compelling, with several surprising plot twists toward the end. There are also a couple that were a bit more expected, but they were not really meant to be completely unforeseen. Cassie's plot line has a bit of a slow burn feel to it, but Zombie's story is much faster paced, so the book never feels plodding. The different plot threads start out separate, but they gradually merge together in a way that is fascinating.
It should also be noted that the writing style is brilliant, simultaneously literary and accessible, with the ability to provide mesmerizing turns of phrase without slowing down the pace at all. The two main points of view are written in first person present, but both voices are distinct and authentic. There are also a couple of minor points of view that lasted only for a couple of short chapters (one of a Silencer, the other of Cassie's younger brother), both of which were written in third person present and contributed to the novel as a whole.
Readers should be aware that there are around five f-bombs interspersed throughout the novel, as well as some milder language, and that the violence is frequent and brutal. Sexual content is kept mainly to kissing and a couple of discussions of sex, but there are several romantic plot threads, which might annoy some people who don't like anything resembling romance in their novels. However, they add a lot to the story and are key to enabling growth in several major characters, including Cassie.
This is easily one of the best books I have read, sitting at number three or four on my list of favorite books. With a broad mainstream appeal and an extensive marketing campaign, this book is set to make a major splash commercially as well as critically. This book genuinely deserves to make it big, unlike many of the novels that have gotten extensive backing from publishers in the past.