Dexter is back — and it seems like he's loving life! The episode begins with views of domestic bliss — Dex flying a kite with Harrison, going bowling, sexing up a random woman (as the last petal from Hannah's orchid ominously falls from the stem onto the bedside table) — interspersed with scenes of him carrying out his bloody work, both legal and extralegal. "There's nothing like a crisis to define who you are," he intones in voiceover. "A better person would feel bad about LaGuerta's death. But the truth is, it solved all my problems."

Our Miami Metro gang gathers for a dedication ceremony for the Captain Maria LaGuerta Bench, which Batista sees as a shameful tribute to the woman he loved. (He also mentions that it was her death brought him back into the law enforcement fold.) Everyone asks Dexter about Deb, since no one except Quinn has heard from her — and even Quinn hasn't talked with her recently.

Cut to: Deb doing a line of coke before a hot scruffy guy in his boxers snogs with her. He calls her "Debbie," talks about his need for "a fence," and muses about how serendipitous it was that he met her. "It's funny how something as simple as you walking in that door could change everything." Um, yeah — spoiler alert — he has no effin' idea.

Dex breaks into Deb's house and finds prescription and recreational drugs, then goes to visit her new employer, a dapper private investigator. This guy, Elway, says that Deb has always been unpredictable but has never gone so long without checking in. Dex asks about her most recent case, and Elway tells him Deb was looking into a bail-jumper named Andrew Briggs. (Read: Hot Scruffy Guy.)

Meanwhile, Dex has, you know, his actual day job to worry about. The latest murder victim is a guy who was shot point-blank in the chest. As Dex examines the body, the back of the poor sap's skull falls off, revealing that the killer had scooped out part of the brain.

Dex researches Briggs and finds that he stole $500,000 of jewels before skipping out on his bail. Seeing his arrest record, Dex worries that Deb is over her head. So he does what every loving sibling does and hacks into her bank account, cleverly guessing her password: f—kingpassword. He sees that she frequents one convenience store in particular, so he heads there and eventually spots her — kissing Briggs.

He corners her in an aisle, startling her. She's understandably less-than-happy to see him and reveals that she's getting close to Briggs to get the jewels before Briggs fences it. Dexter asks the clearly-mature question: "Are you having sex with that guy?" Debra responds "My life is none of your business" (and she really emphasizes the sssss in "business").

Then Deb delivers the first of three cutting blows to Dex this episode: "I don't wanna talk to you," she says, "and I really don't wanna f—king see you … Why? Um, because you made me compromise everything about myself that I care about. And I hate you for it … I shot the wrong person in that trailer."

Dex drives off in a rage, fuming to Dead Harry about it. When a fellow motorist makes the mistake of cutting him off on the roadway, Dex forces the fellow off the road and puts him in a chokehold, only stopping when he sees the guy's Harrison-aged son in the backseat.

To give us a little relief from all the drama, we're then treated to a scene of topless Jamie humping Quinn. (Yep, they're a thing now.) Their sexy times come to an abrupt stop, however, when Batista comes home. As Quinn hides in her boudoir, Jamie tells her bro that she was just doing some cardio. (You bet you were, Jamie!) Batista is preoccupied by Maria's possessions, including cell phone records of Deb's and Dex's, from which he infers that she couldn't let her (ultimately accurate) hunch go. Later, he gives Dexter one of Maria's vases and realizes that Dex still hasn't forgiven her. "It's complicated," Dex says. (You bet it is, Dex!)

At the briefing the next day, Deputy Chief Matthews introduces Dr. Evelyn Vogel, a neuropsychologist and former consultant to Miami Metro who specializes in pathologizing serial killers volunteer with the case.

Vogel tells the gang that her curiosity was piqued when she noticed that the killer has removed the empathy-producing part of the brain. She posits her theories about the serial killer while keeping a steady eye on Dex. Later, she has a one-on-one chat with Dexter and pries into his thoughts on the Bay Harbor Butcher, telling him she believes that the Butcher is no less than a psychopath. Dexter is rattled.

Quinn, having looked into Brigg's fence at Deb's request, tells Dexter that there's no information any guy with the name El Sapo. He also tells Dex that the jewelry store Briggs robbed happened to belong to a mob boss, so no one wants to buy the jewels. Dex does some digging and realizes that El Sapo isn't a fence at all — he's a hit man.

Worried that El Sapo will take out Briggs and kill Deb in the crossfire, Dexter tracks her down. Thanks to Quinn, he knows the motel she's calling home. He finds her there and tries to warn her about the danger, but she almost wants to die. "I wake up every day thinking of every bad decision that I ever made because of you. And it kills me that I can't take any of it back." (Zinger #2.)

Briggs catches them talking and recognizes Dexter from the convenience store. Dex tries to take Deb away, but Briggs stops him. They fight and both reach for a knife, but Dex gets it first and stabs Briggs to death. "I felt okay around him!" Deb moans. (That's a pretty low bar, huh? Poor Deb.)

Dex tries to tell her that she's lost, but she objects. "I know exactly where I am," she seethes. "And I'm in some f—king hell, which is exactly what I deserve. But you — you are lost. All my life I thought I need you, that I couldn't survive without you. It was the other f—king way around." (Burn #3.)

As Dex returns to Harrison — realizing too late that he literally has blood on his hands and that he is indeed the lost one — Deb calls in the "suspected homicide" and gives her statement to the cops. She calls Elway to say that she thinks she knows where the jewels are. But what she doesn't notice is that she's being watched by El Sapo.

The next day, Dex sits on the Captain Maria LaGuerta Bench and looks over the beach where he just recently flew that kite with Harrison — but now he sees it as a dirty, desolate, joyless place.

Vogel comes, hoping to talk with him. He's not in a talking mood, so she leaves a folder with him. He opens it and sees morbid crayon drawings, all of which are signed — in a child's scrawl — by "Dexter." He chases Vogel down and slams her up against a wall.

"You can't kill me," Vogel says. "Why?" demands Dex.

"Because I don't fit Harry's code."

What the what? See you next week!