This episode really explores Dexter's character. He realises how his 'fake' life is starting to feel real to him, and no longer wants to lose that aspect. Dexter turns into a hypocrite as he goes against Harry's code - which he states is outdated as he's began to live real life.
We are re-visited by Doakes, which was a nice addition to a season that was beginning to feel stale (ever since Victor's death in all honesty). Quite frankly I'm glad La Guerta is dead. She was boring me, and was beginning to be an uninteresting Doakes.
However, the main plot line derives from the conclusion - Deb being the killer. Dexter challenged Deb to kill him, role-reversing the situation he found himself in with Hannah McKay mid-season. How Deb will handle this is what will prove to be crucial next season, which may make her character somewhat interesting, but I still want the focus on Dexter and how he hopes to aid in her recovery.
It will be interesting to see what the main focus is, and as to whether we will explore 'human' Dexter further or the serial killer that has been absent for a prolong amount of time this season (his urges have began to degrade as he's become more human like - will the opposite happen for Deb).