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.