Dexter returned from his brother's bonding trip to Nebraska, and immediately apologized to his sister. She's all mad at him for missing a few days of work, but at least he didn't go on a homicidal killing spree or anything, right? Actually he kind of did, but pulled back before things got really ugly. Fortunately Dexter was able to ply Deb with a cruller, and she gave him an important update on the Doomsday Killer investigation: the killers have been re-nicknamed, and are now being referred to as DDK, joining an impressive list of initialed evil-doers ranging from BTK to KSM to and DSK.



Nicknames aside, there were three important developments in this 'Dexter' episode, 'Sin of Omission.' Professor Gellar exacted his revenge against Travis, brutally murdering his sister and setting her up as "the whore of Babylon." That development served as a catalyst for Dexter to turn Travis against Professor Gellar. And lastly, and perhaps most importantly for the big-picture health of a series that was just renewed for two more seasons, was the 'Dexter' writers again playing with the idea that Deb could find out the truth about Dexter's double-life as a serial killer of serial killers.

From the beginning of the episode, there was little doubt that Gellar was going to do something terrible to Travis' sister. You kind of got a sense of it right after Travis uttered the word "vegetarian bacon" while making her breakfast. Gellar made it more clear when appeared from behind the mailbox, declaring that he was on the lookout for the "right whore." Later, when he again almost magically appeared again at her school and clubbed Travis with a shovel, it was clear bad things were going to happen.

And they did. Gellar killed her in a heinous way, carving some message into the flesh of her forehead and chaining her to a chair .. he called it his "whore of Babylon." More interested in killing Gellar than arresting him, Dexter stole evidence from the crime-scene and used it to locate Gellar's lair, where he found Travis chained to the floor, and so hungry for revenge that he vowed to help Dexter take down his former mentor in murder.

We also officially entered the sweet-spot of a 'Dexter' season, a several-episode chase between Dexter and the main villain. Now, after Gellar saw Dexter rescuing Travis and Dexter knows where Gellar's hiding, the hunt is on. Of course, there's always the variable of the Miami Metro investigation, which now at least has Travis as a prime suspect, but a face-off between Gellar and Dexter is inevitable, and something to look forward to.

But let's get to the Deb and Dexter storyline, which was a subtle but important part of this episode, as the 'Dexter' writers began to toy with the idea of Deb finding out about Dexter's secret double-life. This is something that they've come close to but backed away from before, most notably in Season 5 when Deb walked in on Dexter and Lumen in a kill-room with Jordan Chase but made the choice not to pursue their identity. But increasingly, she's becoming more aware of Dexter's secrecy and sneaking around.

First, she found out about Dexter's Nebraska trip by finding a pen from the Shady Lane Motel, which Dexter was able to spin away with a brilliant improvisation. "We both had people we love killed by the same killer and I needed someone to talk to," he explained. But his alibi was less convincing when she came over unexpectedly to cook steaks and he disappeared with only the vague explanation that "something came up."

All of those things seem to be adding up to Deb getting a lot more skeptical of her brother, and between talking about Dexter with a shrink, and feeling some serious guilt after Travis' sister was found dead with her card after she'd interviewed her for the investigation, it felt like Deb may be close to looking at her brother like a detective. The notion that Quinn planted in her head last season that Dexter may have been involved with the Trinity Killer remains suppressed in her mind somewhere, and Dexter's behavior may force her to confront it soon.

That would be an excellent development for the show. As good as it is, Dexter threw away any semblance of believability away a long time ago. Fans don't watch the show for realism. But for the integrity of the story, isn't it about time someone caught on to him? Even an ace forensics episodes can't kill this many people, surviving every near miss with his anonymity in tact for this long. And if anyone's going to uncover the truth, it should be Deb. Will the show have the courage to see that storyline through? We have two-and-a-half more seasons to find out.

A few other thoughts:

There was a great show-down scene between Deb and La Guerta. In an argument over a dead prostitute that La Guerta wants declared an overdose to juke the stats, she lays down the law. "Find the man who killed four innocent people, not some John who bailed on a fucking junkie prostitute who overdosed. That's an order, Lieutenant." It seemed convincing and oddly sensible in the moment, but a minute later she was on the phone with someone, telling them she'd made their problem go away. I wouldn't be surprised if it was Captain Matthews, who we know has a thing for prostitutes.

Earlier in the season, I was hoping that Dexter and Brother Sam would team up as a crime-fighting duo to solve the Doomsday Killer case. Now that Sam's dead, I'll settle for the poetic justice of Dexter using his extensively annotated, blood-stained Bible to crack Gellar's code.

One of the bits of biblicaly-inspired wisdom Dexter dispensed as he was trying to turn Travis against Gellar was that even if he was no longer killing people, if he didn't try to stop Gellar's rampage, he was committing a "sin of omission." I couldn't help but think of the Penn State scandal.

The scene where Gellar told Travis that he killed his sister was as intense and chilling as any we've seen this season. It reminded me of the recent 'Sons of Anarchy' scene where Unser told Opie that Clay killed his father.

What did you think of this episode of 'Dexter'? Sound off in the comments.

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