First of all, we have gotten to a point where Dexter feels like he has finally gained control.
This episode shows how you can weave intricate webs and storylines to have a great payoffs and moments within the series mid-term. Like :
The scene that started the storyline of Maria starting to believe Doakes being instable lately with the 2 shootings within 6 months... tied with him tailing Dexter for few months.
Another one with Rita and her mother being so controlling to reach the dramatic point this episode which makes Dexter between him viewing what is Contol and be Human and inclusion of Lila which leads to the last moment in the series- - and my favorite one so far which I will talk about at last.
All these storylines with Buildups over a season or almost that gets paidoff when Dexter confronts Doakes and frames him. Also, the moment where Dexter says - "They are still playing my tune. It's like I'm conducting a final symphony - requiem for demonic Dexter." He frames Doakes, makes whole Department dance in his tune. But here comes a moment - "Hey, you got your light fixed"
Lila, the one who made Dexter feel in Control can control him without any suspection as she said ... she will always get what she wants.