You guys, seriously, this show is making some pretty interesting choices; it goes to show how much more conducive it is to writing a good story to have the end in sight. So:

LaGuerta stops by to see the old Captain and tells him her theory about the BHB; since he just so happens to own a boat, he's on her list of people to follow up with. Given how she cost him his job, he's understandably snippy at first, but later, he tracks her down and offers her information on the people on her list (of cops who own boats, essentially) if she'll help him get his pension reinstated. It's a classic pairing of people who don't remotely trust each other, with good reason, so it should be fun.

Two charred corpses lead MM (well, Dexter, really) to conclude there's a serial arsonist-murderer out there who's been wearing a protective suit so he can watch his victims burn alive. Could it be the random arson investigator who seems just the right amount of creepy to be a secret killer? Probably!

Dexter goes to Deb and tries to make her feel better about her confession, telling her that he understands since they've been the only constant in each other's lives. This does make Deb feel better, but meanwhile, Dexter's bond with Hannah is growing ever stronger. Also, in the wake of the failed attempt on his life last episode, Isaak Pullo gets a tip that the Brotherhood has sent two more assassins to take him out. These men are known to him to be the deadliest of the deadly, so Isaak Pullo, needing help from a source of whom the assassins are unaware (i.e., not Lurch), goes to the only other killer he knows – Dexter. He offers Dexter his life if he'll help him, and although Dexter initially refuses, the offer does intrigue him. He ends up being forced to accept, though, when Isaak Pullo, having had Lurch keep tabs on Dexter's movements, kidnaps Hannah to use as leverage to insure Dexter's help. Isaak Pullo promises that if Dexter goes along, he'll not only free Hannah but will drop his death mark against Dexter and will walk away from Miami forever.

While they're thrown together, Isaak Pullo, long fascinated by his nemesis, tries to get into Dexter's head, but Dexter's the one who wins their mind games as he realizes that Isaak Pullo secretly blames not Dexter but himself for Viktor's death; still, Isaak Pullo realizes that Dexter is having trouble facing his feelings for Hannah. Dexter ends one of the assassins before he ever knows what hit him; aware that this means Isaak Pullo is on to him, the second assassin goes to Jason Gedrick for help finding Isaak Pullo, and Jason Gedrick gets the bright idea to track down Dexter, with the idea that Isaak Pullo won't be able to stay away from him. Unfortunately for Team Brotherhood, the Dexter/Isaak Pullo alliance accurately anticipates this development and picks off the second assassin, but still, all doesn't quite go according to plan – more on that later.

Despite her assertion that she'll never approve of Dexter's relationship with Hannah, Deb helps Dexter where she can in his efforts to save her – and she's the one, once Dexter points her in the right direction, who tracks down the spot where Lurch is holding her. However, Hannah the secret killer is not one to let the grass grow under her chains, and manages to hoodwink and kill Lurch, but not without suffering a stab wound that would have turned out to be mortal – if Deb hadn't shown up to save her. In the hospital, Hannah points out that Deb could have let her die, but Deb tells her that that's not who she is – she's not like Hannah. I guess if she had to save her life, rubbing that sentiment in her face almost made it worth it.

So, getting back to the second assassin, Dexter and Isaak Pullo's trap works perfectly, and while Dexter mops up the guy's blood, Isaak Pullo heads off, intending to leave Miami and fulfill his promise. Unfortunately for him, Jason Gedrick has been having a really bad day -- annoyed that Quinn wasn't returning his calls, he banged Nadia (well, that part probably wasn't so bad), so Quinn beat the crap out of Jason Gedrick and took Nadia out of the club. Between that and the failure of the assassins, Jason Gedrick decides to put a bullet in Isaak Pullo himself, and although it's not immediately fatal, Isaak Pullo knows that the fact that the bullet is still in him means he's a dead man. His dying wish is to be buried at sea so he can be reunited with his love, so Dexter, kind of touchingly, makes that happen. Isaak Pullo's dying advice is for Dexter to go for it with Hannah; he was like Dexter before he met Viktor – detached and coldly logical – but with Viktor, he never had to hide who he was. So in the end, Dexter crawls into Hannah's hospital bed and tells her he doesn't know where they're going, but he feels safe with her. And like the title says, it's crazy, and it's stupid, but it's love.