I was worried that, after Isaak's death, this would be the episode where the season lost all momentum. And I've read some reviews and responses that indicate that. But watching it myself, I actually really enjoyed this episode.
I've been feeling like this Hannah McKay story was an adequate but unremarkable B-story that was just chugging along in the background to give characters something to do in between the more important stuff. But this episode was the most convincing the Dexter/Hannah relationship has been for me, thanks largely to the consistently brilliant Jim Beaver showing up as Hannah's father. There was some great character work in general going on in this episode. And LaGuerta's investigation, long bubbling in the background, is now taking on an increased urgency, and it's kinda thrilling seeing the jigsaw pieces snap together, and Dexter's house of cards start to come tumbling down.
While the Isaak story might have ended prematurely, it seems like we're setting the stage for a finale that brings things full circle to the Deb/Dexter relationship and the moral questions of Dexter being unmasked as a killer that were at the fore in the season opener. I honestly wouldn't be surprised if that season-opening red herring of Dexter on the run ends up being how the season ends, only this time it's for real.