"I'll face the depths by myself."
Dexter is once again alone, if you don't count the Dark Passenger. After Deb spends the entire episode protecting Dexter in several cases from her fellow police officers, she realizes she cannot continue to be a part of Dexter's darker activities and ends their sharing of information.
Not that anyone can blame her. After all, she found out about LaGuerta's private digging into the Bay Harbor Butcher case and recent disappearances. She had to cover-up one of Dexter's mistakes after he was caught on film.
Deb does get to see the upside of Dexter's killing, however, as the missing man's son reveals his gratitude at the man's disappearance for it ended the man's habit of beating up his wife.
Deb also has to lie to Batista, her former partner, shutting down his suspicious that Alex's suicide wasn't really a suicide. She behaves just as LaGuerta did to her last season, alienating a former friend and closing a reasonable trail of thought to protect someone else.
Mainly, tonight's episode was about catching everyone up on everyone else's past actions.
Dexter figured out that Louis was killed on his boat (not sure how the meticulous sociopath missed the blood in the cabinet) and that it was done by Isaac.
The cat and mouse game switches, now that Louis is dead, to include Isaac. Isaac makes the first move, waiting to snatch Dexter up after he comes home. Dexter counters, luring Isaac to a public café before he walks in. Isaac follows that up by threatening Dexter's sister.
If I were a maniacal killer, I'd probably see a few conspiracy theories as well, but Isaac stretches to make the idea fit that the other cops of Miami Homicide are guilty of killing Viktor.
After warning Deb of the mess he'd made for her (by making her a target of the Ukrainian mob -- not part of her everyday enemy list), Dexter sets Isaac up, baiting Isaac into entering a Colombian hangout.
While Dexter believes that is all that is needed, Isaac proves to be every bit the adaptable and resilient killer worthy of playing against Dexter in the twisted game they call life. After all, winner gets to keep their life.
When Dexter is called to a crime scene, he sees that Isaac annihilated the Colombians. Dexter uses the justice system for a change, allowing Deb to arrest Isaac and put him in jail rather than a trash bag destined for the ocean.
Dexter's visit to jail is a draw, however, as Isaac reveals his intent to wait Dexter out, bide his time during his imprisonment until he gets vengeance for Viktor's death.
Meanwhile, Dexter somehow has time to do his actual job. He works with Hannah and Batista to recreate Wayne's killing spree from when he was in Miami. As she handles some of Wayne's 'trophies,' there is a moment where she appears to reminisce fondly on the deaths rather than to remember Wayne's terrifying ways.
Out at one of Wayne's body dump sites, Dexter finds actual forensic evidence that supports his conclusion that Hannah was not the innocent victim. Instead of telling Batista his suspicions, he confronts Hannah. He explains how the murder of the couple actually happened, ignoring her futile protestations of innocence.
Ironically enough, Dexter shares his first crime scene with Hannah after she relates her memory of the first time she saw Wayne kill. We know Dexter is lying, as the first crime scene he was at was the one he was a part of -- his mother's -- when he was a small child. Therefore, Hannah could be lying as well.
Oddly enough, the two appear to connect over this exchange of gory detail and it clearly isn't a good thing. Hannah lacks all methodical precision that Dexter is ruled by; they are opposites (as far as the murderer spectrum goes), and in this case I really hope opposites don't attract.
Although Deb says differently, Dexter still seems to be the "hero" he was way back on their childhood family vacation. He's still saving her from the ugly, hard parts of life, swimming into the deeper murkier waters so that she can keep her feet clean.