The clues are starting to be pieced together. The Bay Harbor Butcher, it's found out, is one of Miami Metro PD's own. A big shocker to all in the know.
Meanwhile Dexter has his own stuff to worry about. Lila is super clingy (and a bit of a pyro) but in this episode she took things a step further. Not only did she break into Rita's place suspecting infidelity (toward the end of the episode), but she also called Jiminez, one of the men who killed Dexter's mom, telling him where Dex would be one night. Jiminez stabs Dexter but gets away. Our (anti)hero realizes he cannot let this go unpunished. And wising up, Dexter realizes he cannot be with Lila anymore.
Meanwhile Lundy and Deb have their first date. Doakes blows off an interview at a private security firm to actually break in to Dexter's place, and eventually finds the slides with blood samples hidden in the A/C unit.
The suspense is building every week, and Dexter is still one step ahead of the investigation… for now.