In the car, Hannah is talking about what a game-changer the appearance of the marshal is. I don't disagree that it ups their urgency but they can't really have been planning to stay in Miami regardless, can they? Being a hot blonde certainly comes with some benefits, I'm guessing, but she's notorious in this town and easily recognizable. Dexter thinks they should focus on getting the money, which certainly has a level of wisdom to it. Hopefully he realizes that speeding is likely to be counterproductive here.
Deb has apparently given Quinn the information that Zack was at that motel in the Keys. Although she surely stopped short of informing him that he should really, really not waste his time looking for the kid. With Zack exonerated for Cassie's murder, Quinn sighs that he really wants to solve this one for Jamie, especially since he hasn't been there emotionally for her lately. After the two of them have a good laugh about Quinn providing that kind of solace to anyone, Quinn confesses that Jamie routinely accuses him of comparing her to Deb. But this -- understandably enough -- is a bit too awkward of territory for Deb to cover, so she shifts gears and suggests Quinn question Jamie again, given how close to Cassie she was. Quinn, however, admits that it's tough for him to play both cop and boyfriend in this particular situation. So Deb offers to do it for him, and if she was wary of giving him advice about Jamie I can't imagine how she thinks subbing for him in questioning Jamie is going to be comfortable for anyone. But no one ever accused Deb of being the most logical person on this show. Also, it's not like he's kissed her.
Dexter and Hannah arrive at Arlene's, and the place is far from the crack trailer you'd expect, so apparently Arlene's had some interest in Hannah's money beyond playing safe-deposit box. When Arlene (better dressed but sporting the same cheap rinse as before) opens up, she's like, "Hey asshole that turned Hannah in." But she has them enter anyway and asks with mild curiosity how their reconciliation is going to work. With all the obstacles in their path, it's impossible to conceive of a short answer that remotely begins to address the question, so Dexter's reply of "We're figuring it out" seems pretty much like his only play.
Arlene leads them into the bedroom and pulls a suitcase out of the closet while explaining she told the kids there are snakes in it so they wouldn't disturb it. While I kind of admire her casual willingness to scar her children, I still wonder if this is the most secure arrangement Hannah could have come up with. No time to wonder about that now, though, as Dexter looks out the window and sees that Clayton has arrived. Thinking quickly, he tells Hannah to hide and Arlene to act like she's got nothing to hide. Sure, ask the former (?) junkie who's afraid of losing her kids to play it cool, calm, and collected. No problem!