I was going to begin my review by stating that Brother Sam was wearing thin, but then he got shot and I'm waiting to see what happens with him. While Mos Def has been great, the only bright light in an otherwise bland new characters, the writers didn't give him anything to do other than repeat religious platitudes. It was the doomsday end of the world stuff from Gellar, but the generic statements everyone knows by heart. Maybe Sam getting shot will improve his character--or maybe he'll die and that's the last we see of him.
Generally, Dexter is the smartest character and doesn't do anything stupid other than think the most obvious things during his voiceovers. In this episode, though, it seemed like he was competing with Quinn for dummy of the week. First, Dexter finds it necessary to compare Travis's Bible pages to the rectangle cutouts, when it would be plainly obvious to anyone that they were the same. Even then, all Dexter does is look at the rectangles without even taking them to try to fit into the cutouts. So why look at them in the first place? But Dexter decides to be even more stupid, letting Travis go after he says Gellar's been killing. While that may be true, how about some extra digging. Dexter always gets the truth when he's on the hunt--except when it comes to main villain. Come on, writers.