The Cold Moon - Jeffrey Deaver.
In a word, horrible. I've read a lot of Deaver, and some of his books - like The Sleeping Doll, The Stone Monkey and The Burning Wire - were excellent. And others, like Roadside Crosses, The Empty Chair and The Broken Window were weak. I don't think he's ever actually written anything I didn't like ... until now.
The Cold Moon suffers because of a schizophrenic plot. The initial setup is okay, with a lunar-themed serial killer prowling around New York and a sub-plot about a corrupt police precinct, and if the book had ended after about three hundred pages, it would have been quite clever because of the typically-Deaver twist. But then the last hundred pages feel like they were written with whatever leftover and half-baked ideas Deaver had lying around. What starts out as serial killers and corrupt police turns into vigilante justice, domestic terror plots and even a heist setup. There are so many twists and turns that it keeps doubling back on itself.
I think I've said this before, but the major problem that I have with Deaver's writing is his tendency to write to a "theme". Some of his books, like The Broken Window and Roadside Crosses are based around a core concept (in the two cases I mentioned, data mining and social media are those concepts), and are invariably weaker because it feels like Deaver is trying to make a social commentary. The Cold Moon doesn't suffer from that, but as is the case with many of his non-themed books, it has a problem of bouncing back and forth: events play out in a certain way, then it is revealed that the heroes intervened in time, and Lincoln Rhyme explains how they prevented it. The Empty Chair did this - a character was presented as an expert on a very particular subject, and he ruled a certain theory out. The reader was given no reason to question this character, and so accepted the opinion as valid ... and then, two hundred page later, it was revealed that the expert was wrong all along. It's noticeably worse in The Cold Moon because there are half a dozen sub-plots stacked up on top of one another that come out of nowhere, end just as quickly, and are all melded together than I cannot figure out what the actual plot was. It's just walls of exposition explaining why events in the chapter you just finished reading did not actually happen the way you actually read them.