Hmmmm.....two and a half stars? 3 for plot and a nice mystery with some significant twists. But epic fail for the annoying characters. There are times when you love Dexter, specifically at the beginning, when you're getting to know him, and then he just becomes a snide, egotistical, silly and hypocritical prick. I disagree that this book should have been longer, with more development. I think it would have worked much better as a short story. Dexter spent half the book reciting the "Code of Harry," while spending pretty much every chapter after chapter 2, breaking it. One could argue this shows growth on Dexter's part, how he's becoming human and gaining emotional insight, but I thought it was pretty superficial. And Deborah! No redeeming qualities whatsoever. If I were Dexter, the end may have been a little different for dear, dopey, dimwit Deb (and that is my poke at the incessant alliterative "cleverness" of Mr. Lindsay.
A really brilliant idea for a story, very poorly executed. Still. I want to know what happens next and there are significant differences from the show that I still want to read. If you have a choice, watch the show.