I have to say, my first reaction is that this was the best episode in memory – thematically cohesive and emotionally resonant – even though it's really a bridge to the action that surely is coming in the final four eps of the season. So:
LaGuerta keeps digging and finds the extremely salient information that Dexter left his old boat slip with eight months to go on his lease – right after the Bay Harbor Butcher case came to light in May 2007. In the end, she locates the Slice Of Life, and I have no idea what she's going to do with the information but it can't be good.
Even as he's struggling with Deb's request from the end of last episode, Dexter gets to know Hannah and learns that she still longs for her vision of Argentina, where, as you'll remember, she and Randall were supposed to end up – especially since she and Randall talked about having a big family, and the way she talks about it makes it seem clear that she was genuine when she said last episode that she wanted kids. Dexter goes to Deb in hopes that, in the cold light of day, she'll recant her request for Dexter to kill Hannah, but that hope is futile, as Deb has even gone to the trouble of vetting her for him. Dexter first tries to stonewall Deb on the basis of evidence and then attempts to convince her that she won't be able to live with herself, but between Speltzer and Price, Deb stands firm in her conviction that Hannah must die before she kills again. Dexter mixes in some truth about how he cares about her and how their father would back him in putting his foot down, and later, Deb tells Dexter that maybe he was right, and things seem okay – until Dexter carelessly lets it slip that he and Hannah are A Thing. This leads to an AMAZING breakdown from Deb in which she finally lets slip the reason she went to the church that night, and as horrible an idea I thought Deb being in love with Dexter was, it's used effectively here. Dexter, understandably for once, has no idea what to say to Deb, and she tells him to get out so she can self-loathe in peace.
Isaak Pullo succeeds in losing his police tail, but when he figures out that Isaak Pullo is still after Dexter, Jason Gedrick gives him the advice to drop the revenge quest, as it can only lead to trouble that would be very bad for business. Isaak Pullo, however, does not take the advice to heart, and it's only via a luckily-timed drop of his keys that Dexter avoids instant death from a bullet shot by his nemesis. Feeling like Isaak Pullo has become a loose cannon, Jason Gedrick goes behind his back to someone else in the Koshka hierarchy; from there, he approaches Quinn and, with the aid of a recording of the time Quinn agreed to steal the blood evidence from MM, gets him to supervise a drug shipment coming in that night. We don't see how the latter part develops, but it looks like Jason Gedrick is running the Miami Koshka show now.
Having kept tabs on Isaak Pullo and learned that he's staying in Viktor's old place, Dexter resolves to wait for Isaak Pullo to come home and kill him there – only to find, and kill, a Jason Gedrick-approved assassin there for the same purpose. With a cooling corpse in front of him, Dexter is forced to flee the scene; later, frustrated by how difficult to kill Isaak Pullo is proving to be, Dexter tells Hannah all about his difficulties, and she Murder Coaches him, suggesting that even though he already knows Isaak Pullo to be a killer, Dexter should vet him normally in the hopes of finding his weakness. Meanwhile, recognizing the dead assassin, Isaak Pullo realizes that he now has a Koshka death mark on his head; also knowing that his police tail gives him an alibi, he reports the crime and takes the opportunity to casually and hilariously throw accusations in Dexter's direction. In the end, Dexter tracks Isaak Pullo to a bar, intending yet again to kill him and instead having a drink and listening to Isaak Pullo come out to him – and tell him Viktor was his soul mate. In the best-written scene I can remember on this show in ages, in an eerie parallel to what's going on with Hannah, Isaak Pullo recognizes that on some level, he and Dexter are kindred spirits, but he says that's not going to stop him from taking Dexter's life.
Oh, and also? Astor is a pothead.
As Dexter enters Hannah's kitchen to find her chopping herbs, DVO wonders if Deb's call was just a bad dream or if she really wants him to kill Hannah. Dexter asks how he can help, and when Hannah asks him to dice something, he picks out a cleaver reminiscent of the one used in Delicatessen, and given this show's subject matter I'm kind of surprised it took me this long to make that reference. Regardless of the size of the weapon being wielded in her presence, Hannah is clearly enjoying Dexter's company, and the fact that he uses the thing only on the herbs probably helps.
Cut to Hannah bringing their plates out to the table, whereupon Dexter, pointing out the calendar that I believe is from 1996, makes a joke about it before noting that it's the year she ran off with Randall. Hannah, however, says she keeps it not for that reason but because the picture she has it open to is of Argentina, which she imagines to be "nice, happy. Home." Dexter then gets a text from "my sister and my lieutenant," and frankly I'm surprised Hannah doesn't start slapping him right there in an homage to Chinatown, but she is taken aback that the woman who in no uncertain terms called her a murderer just the day before is Dexter's kin. Hilariously, Dexter is like, "Yeah, I didn't mention that," and Hannah agrees that he did not indeed. They both laugh, and then Hannah wonders if what they're doing is crazy; she then goes on that she knows they agreed never to see each other again, so if the night before was a one-time thing, she's okay with that. "But if you never want to see each other again tomorrow night, then I'm okay with that too." Dexter's completely noncommittal about the whole thing, which, luckily, Hannah seems to find charming, but DVO is preoccupied anyway with the idea that he's got to find a way to get her out of Deb's head. Don't worry, Dexter, now that Price has been dead like a whole twelve hours, I'm sure Deb's ready to move on.
Speaking of Deb, she opens up for Dexter and offers him coffee, which she's apparently made in abundance since she "couldn't fucking sleep." Forestalling his errand for a moment, Dexter accepts, but he sees even more clearly how cut out his work is for him when he observes a bunch of Hannah-related material Deb's apparently been examining. Dexter cautiously asks Deb if she really means what she said the night before, and she evenly tells him yes; not only that, she's already vetted her for him. So among all the reasons Deb's going to lose it later, we can add the fact that she did all this work it turns out Dexter had already done. Dexter tries to play obstructionist, telling Deb she doesn't even know Price was murdered, but when Deb plays Price's tape of Hannah's confession, the point becomes hard to argue. Dexter tries anyway, telling Deb that Hannah was just a kid back then, but Deb won't back down, so Dexter has to flat-out tell her he's not killing Hannah. Deb gets emotional as she tells him how hard it was for her to ask him to do so, and she tried and tried to come up with something she could use against Hannah, but ultimately, she can't let her kill again -- not after what happened with Speltzer. "You're all I have left." Dexter looks at her, honestly unsure what to do, but his phone lets him know he has a text - from Astor, saying her grandfather's kidney stones are acting up. I've had gallstones, which I think kidney stones put to shame, so I'm going to say OUCH for poor Grandpa. Having had a moment to think, Dexter reminds Deb that she told him she didn't want to be part of his world, and if she could hardly live with herself for lying to Batista, how's she going to feel about essentially ordering someone's death? Deb, however, informs Dexter that there's actually quite a lot she can live with these days, but Dexter tells her he cares about her too much to let her do this, and by the way, Harry would back him up. Deb is forced to accept this, prompting DVO to intone, "Even though everything I said is true, it doesn't make me any less of a liar." Thanks for saving me the trouble, DVO. For once.