If you are reading this review, you've already made it through the first two books, and you want to see if the conclusion is worth your time.
It is.
This is an action-packed story, set two years after the Fall of humanity at the hands of the vampires. The characters from the first books appear to be the only resistance, and they have to figure out how to win back the world. All while the main character, Eph Goodweather, tries to also free his son, taken captive by his vampire ex-wife in the last book.
What follows is a page turning thrill-ride, with narrow escapes, decent characterization, and finally, a backstory explanation and conclusion. As with the previous books, this is very well paced and will hold your attention as you read through to the very end.
It is not without flaws, however. The backstory was adequate, but a departure from the rest of the series. From the start, the authors have soaked us in the scientific aspects of vampirism, including its spread and the biology of a vampire (to be fair, ripped from Del Toro's movie, Blade II). The ultimate explanations are more mystical than scientific, and it seems odd to have gone to all the trouble of making two main characters scientists and exhaustively explaining the biology of vampires, only to make the origin decidedly non-scientific.
Whatever. It wasn't enough of a problem for me to have not really enjoyed the book, just not getting the fifth star from me.
If you have gotten through the first two books, you really should finish the trilogy. You'll have fun, and that's really what these types of books are about, isn't it?