Dexter visits Hannah in prison, who confesses that she did poison Deb while bitterly reproaching Dexter for choosing her over Hannah. She does promise not to tell anyone about him, if only to lord it over him, and he almost has a breakdown about how he's going to miss her, but he won't consent to getting rid of the poisoned pen, which would result in her release, so they say goodbye. Hannah then calls Schram for help, and we don't hear her request, but she's feeling good enough that when Deb shows up to her arraignment, she rubs her hypocrisy in covering up Dexter's crimes in her face extremely gleefully. In the hearing, Schram uses a fake breakdown to hug Hannah and slip her something that Hannah ingests; soon enough, she's having some kind of seizure in the back of an ambulance – only to escape the hospital once she comes to and everyone's back is turned. She stops by Dexter's to leave him a remembrance, and even though these seasonal contracts rarely vary their routine, I hope we haven't seen the last of her.
Within the first few minutes, LaGuerta turns up to Dexter's place and personally arrests him…for Estrada's murder, and him being perp-walked through MM was no dream sequence, which is truly amazing. She goes on to interrogate him, revealing her personal stake in the investigation; Dexter turns fairly ugly in exploiting that, and things get worse for her when it turns out the evidence on which she arrested him – Estrada's shirt and wallet – were planted by Dexter to make it look like she was trying to frame him. With things having gone south for her, LaGuerta calls Deb in to apologize – but soon Deb realizes she's the fly in LaGuerta's parlor, as she just now got a package from Anderson's widow. Remember when Deb went out to get that gas to light the fire in the church in which Dexter killed Colin Hanks? It so happened that Anderson had ordered the security footage of all gas stations in the area, which means Deb was caught on tape. Deb tries to cover, badly, which only makes LaGuerta press her advantage, and although nothing's resolved, Deb now knows it's just a matter of time before she as well as Dexter are exposed. When Deb tells Dexter what's up, he breaks into her place and finds a warrant to search his and Deb's phone records, which will prove that they were at the church that night, and Dexter, out of ideas, goes to the "LaGuerta needs to die" place.
Meanwhile, Estrada, it turns out, is still on the loose. By tailing his ex-wife, Dexter finds the man in question, and, through a little subterfuge, captures him. He has him call LaGuerta and tell her to come back to the shipping container at which she almost caught Dexter, and when Dexter tells him he's going to kill him anyway, he points out that he killed Dexter's mother the same way Dexter's about to kill LaGuerta. Dexter acknowledges the parallel before taking his revenge, while Deb, having a sixth sense about what's going on, gets the location of LaGuerta's vehicle and figures out what he's up to. Dexter drugs LaGuerta and plans to set it up so it looks like LaGuerta and Estrada shot each other – but Deb gets there before he pulls it off. LaGuerta then comes to and tells Deb to shoot Dexter, and Dexter tells her to do what she has to – AND SHE KILLS LAGUERTA. I mean, it's probably where we should have figured the show was going all season, given how much it's been taking pages out of Breaking Bad's playbook, but oh my God, what an entry into the show's New Year.
On top of all this, there's a series of Doakes "flashbacks." Great to see Erik King and every MF he utters again.
In prison, Hannah, wearing the orange jumpsuit we last saw on Isaak Pullo -- it's been a pretty heavy season on the putting-people-in-jail front for Dexter -- walks out of lockup and sits in the visiting room with Dexter. It's uncomfortable, as you might expect when Dexter has made Hannah a "life partner" in not exactly the way she anticipated, and she looks at him for a long time while he tries unsuccessfully to come up with anything to say. She finally offers that it looks like he got some sun, and he replies, "The boat" before asking if they're treating her okay. She sardonically tells him she gets ten minutes outside a day, and adds, with the same brittle smile, "My cellmate seems nice. She robbed a liquor store so she could buy some meth." Well, Hannah, she may well be nice, but I have to say in that tone it sounds bad.
Dexter starts to apologize, but she cuts him off, bitterly saying that he claimed to love her, but he intones in a voice that will brook no dissent, "You poisoned Debra." And lied about it to his face very convincingly, I will add, since Dexter doesn't. Hannah takes in the expression on his face and decides that further denial is useless, so she tells him it's because Deb was trying to keep them apart, and adds that Dexter could have just broken up with her. I have to admit that solution never occurred to me, probably because, as Dexter points out, that would only have completely freed her up to kill Deb.
Hannah goes on that she's going to spend the rest of her life behind bars, and when Dexter breathes that she left him no choice, she counters that he did have a choice -- and he was supposed to choose her. When Dexter snaps that Deb's his sister, the vehemence of his response leads her sadly to note that she never stood a chance, and you can point out that she would have done better if she hadn't killed Price, but her point is still maybe kind of taken.
She stands to go, but, with his face breaking more than I ever remember seeing it, Dexter gets up and grabs her, begging her not to go. I'd think this is the part where someone would yell, "No touching," but this is going to seem like nothing in a couple minutes. Hannah wonders why he's even there, as she's not going to tell anyone "what" Dexter is. "I would never do that to you." Dexter ignores the frost coming off those words and plows on that he came because he needed her to know that if he could have thought of any other way to keep Deb safe, he would have opted for it. Hannah's suddenly heartened by how emotional he's getting, and when he goes on that he misses her so much, she smiles that she feels the same.