That Hannah — she's a knockout! Literally!

As this episode picks up, Dex is regaining consciousness in some industrial area of Miami. His shrink, Dr. Vogel, calls. (Don't docs just have the worst timing?)

She's calling to say that she's glad Dex didn't kill Zack — her murder-obsessed teenaged patient, and Dex's proto-protege.

Just then, Deb calls, so Dex switches lines. Having been drugged by Hannah, as well, Deb has also just woken up — but luckily, she's still at her house. She comes to pick Dex up. "It was Hannah, wasn't it?" she says.

Dex notices that there are traffic surveillance cameras around, and he thinks he can get her license plate from that footage.

Deb is none too pleased to have Dex's scheming ex back in the picture, especially as the homegirl reminds her of her own descent into darkness. "The moment I asked you to kill her is the moment I started to lose myself," she observes.

That night, Zack drops by Dex's apartment, much to his dismay. He's angry that someone could have followed him to Dex and put two and two together.

Just then, hot neighbor Cassie comes out of her next-door apartment with the suitor from last week's episode; they're going for a swim.

Once they're alone again, Dex advises Zack to stop acting so antisocial, since it will only arouse suspicions. "All I'm saying is that you need some sort of cover life, something that makes you look ordinary," he says.

At Elway Investigations, Deb uses the firm's resources to try tracking Hannah. Elway catches her in the act and is (naturally) inquisitive. Deb tells him, basically, to mind his own business. And Elway loses his temper, angry that Deb seems to be taking her employment for granted. But he gets angry in an aggressive, terrifying way. "Next time, you give a little gratitude," he says, "instead of being such a f—king b—h."

Hey, chump. You watch it. Deb may be a f—king b—h, but she's our f—king b—h.

Dex finds Hannah's van in the surveillance footage, and calls the car rental agency from which she rented the vehicle. Over the phone, he introduces himself as a Miami Metro detective. The woman who takes his call offers up all of Hannah's details freely and gladly — only she used the name Maggie Caster.

Harry appears to Dex and questions his excitement about tracking Hannah. "Hannah doesn't scare me," Dex contends.

"Maybe you need to rethink that," the papa replies.

Elsewhere, Jamie tells Quinn about her intention to move out of her Batista's place. Apparently living with one's brother is not always fun and games. She wants Quinn to move in with her.

Also, Nikki comes to the office to apologize to Masuka after last episode's awkwardness — you know, Masuka deducing that this long-lost sperm-donation daughter might be seeking him out for his money and insinuating as much to her face.

Later in the episode, Masuka goes to the sports bar at which Nikki works and discovers, to his great shock, that it's a topless sports bar. "I didn't realize this place is a breast-aurant," he says.

Using Hannah's contact info, Dex tracks her to a marina, wherein he sees Hannah on a luxury yacht with a well-coiffed gentleman.

Dex follows them to a bougie restaurant but gets turned away at the door for not being on the guest list — or in the right apparel. So what's a serial killer to do? He calls up his young apprentice, Zack, who shows up in the family Lambo (or some such flashy convertible) and breezes past the bouncer with Dex.

Hannah's fella leaves her alone at the bar for a while, so Dex nabs his chance for some face time. She's not surprised to see me. First up in Dex's interrogation: Why did she drug him and leave him in the boondocks of Miami?

"After what you did to me," she says, "I'm not sure you get to ask questions."

Her male friend returns and introduces himself — he's her husband, Miles. And he knows that Dex is Hannah's ex. He and his new wifey exit together.

The next morning, Dex researches Miles and discovers that the guy made his money in international casinos and is worth around $700 million.

Deb drops by, and Dex tells her about his ex's new marriage. "There's someone for everyone, I guess," she quips, drily.

But after awhile, Deb suspecits that Dex is still in love with Hannah. And even little Harrison is thrilled to hear that Hannah is back, much to Deb's disgust.

"Trust me: No one knows what it's like to fall in love with the wrong person like I do," she says.

Later, Deb debriefs with Vogel about the Hannah situation. They agree that Deb can't go to the feds since Hannah knows too much about Deb and Dex's extracurricular deeds.

Zack brings his lawyer to Miami Metro to demand that Batista and Quinn stop watching him. Matthews assures Zack that Quinn will back off, and Batista seconds that motion. Quinn, angry, tells Batista that he's moving in with Jamie. Oh, snap!

Catching Batista in this distracted state, Masuka gets him to grant him and Dex a part-time assistant in the blood lab.

In the parking lot, we learn that Dex was behind Zack's legal aggression. Zack is all eager to get his murderin' on.

"You're going to get your chance, Zack. I promise," Dex says. "Then you'll be able to do what I do: get away with it."

A bit later, Miles confronts Dex at a gas station and threatens him. Dex assures him that there's nothing going on between him and Hannah.

From something Miles said during the encounter — "I'd sooner see her in prison than lose her" — Dex surmises that the dude may be a threat to Hannah. So he texts her, and they meet at her old greenhouse.

"Why did you marry him?" Dex demands.

"Because he was there when you weren't," replies Hannah.

Turns out, Miles is the one who helped Hannah get her new identity as Maggie. But she quickly realized that Miles is too possessive and controlling. So she sought out Dex because she originally wanted him to kill Miles, since if she did the dirty deed, the cops would investigate her and uncover her true identity.

She reveals that she's still heartbroken over the demise of her relationship with Dex. "Despite the shitty way that it ended," she says, "you were it for me, Dexter."

"It was the same for me," he says.

He tries kissing her, but she runs away.

Back at Elway's office, Deb tries to make amends with her boss — "I know I can be kind of a dick sometimes; you don't deserve that," she says later in the episode — but also advises him against crushing on her.

He lets her borrow a GPS tracking device, which she puts on Dexter's car. Cassie catches her in the act, but Deb talks her way out of it. Once Deb introduces herself as Dex's sister, Cassie peppers her with all sorts of questions, trying to unravel the mystery that is Dexter Morgan. Deb basically tells her that Dex can never be solved.

Back at the sports bar, Masuka offers Nikki the assistant position, which she considers. But his concern is unwarranted, she says. "I'm not going to be a stripper, Dad."

Masuka is understandably a little weirded out to be called Dad.

Dexter and Vogel catch up, talking about both Hannah and Zack. She urges him to take Zack's apprenticeship very seriously.

Later, three of Miles's goons ambush Dexter in his parking lot and assault him. He realizes that Miles knows about Dexter's meetup with Hannah.

Back at his apartment, Zack knocks and knocks on Dexter's door to no avail. Cassie hears the commotion and comes out, asking if she can take a message. "Yeah," Zack says. "F—k him." (Some message!)

On the yacht, Miles confronts Hannah about her meetup with Dexter. He threatens to hurt Dex and to keep Hannah a prisoner on the yacht.

Dex shows up and boards the yacht, but by the time he enters the cabin, Hannah is covered in blood. Miles's blood. And Miles is just a limp corpse.

"I tried to run, but he just grabbed me," she says. "I didn't mean for it to happen this way."

Dex helps Hannah dispose of the body, and Deb spies on the duo, having tracked them via her GPS device.

"Do you ever wish that you had followed through in killing me?" Hannah asks.

"No," Dex responds. "Do you ever wish you had?"

"Unlike you, I don't actually enjoy any of this," Hannah reveals. She says she's planning on leaving town.

Just then, Dex gets a page about a new crime scene — on at his apartment building.

He speeds home, but not before making Hannah promise not to leave town before they talk again.

Back at his building, Dexter finds that the victim is Cassie. She was bludgeoned to death. From behind the yellow tape, Cassie's suitor begs Dex for answers, but Dex can't reveal any.

"Norma Rivera was bludgeoned. Is it possible Zack did this when I was with Hannah?" Dex narrates.

"Harry was a good teacher to me because he was normal, human. Can anything good come from putting two killers together? Whether it be student and teacher, or whatever Hannah and I have? Or will it always end the same way, like this?"

Something tells us we're about to find out.

Dan Clarendon is an assistant editor at Wetpaint Entertainment. Follow him on Twitter and Google+!