Before we dive in on this week's installment, let's start with two simple words: "the dentist."

Harrow, our favorite half-faced assassin, who last week spent the episode charming Margaret's children, this week delivers perhaps the most chilling and thematically resonant 30 seconds of the whole season. The D'Alessios are in hiding. Their mother, sisters, and another brother, a dentist, are all in Philadelphia. Harrow offers to travel there. Jimmy asks what for. Harrow says, matter of factly, coldly, sadly: "I would kill the mother. The sisters. And the dentist. That would make them stick their heads up."

If there was any doubt before, it's gone now: This is the new era. This is the passing of the torch. From Nucky's bygone epoch of gentlemen grafters to a bloody world in which everyone is a target, every tactic is permissible, and even innocents are fair game. All of which is unfolding in the black shadow of World War I. It's no coincidence that Harrow uses that precise language — "make them stick their heads up" — a direct allusion to the trenches of Europe.

Also: What a great detail! "The dentist"! This may be the best moment in the series so far.

If last week was all about transitions, this week is about bondage, disillusionment, and escape. So what better way to start the episode than with the writhing face of Hardeen, Houdini's brother, struggling to slip his bonds? Meanwhile, Angela plots a disappearing act of her own, packing her bags for Paris. And two big questions get answered: Who exactly is Jimmy's father (the Commodore!) and why exactly is Gretchen Mol so young (She was 13 when she had Jimmy. The Commodore was 54)?

In a scene that echoes Luke and Darth Vader — we could almost hear the labored breathing — the Commodore coughs from his death bed to Jimmy, "The wrong man is running this town." (Also, if you still have this week's episode on DVR, check out a clever joke in this scene's set dressing: The canopy of the Commodore's bed exactly mirrors the lining of his little dog's coffin.)

Nucky and Margaret sit down with Hardeen, who unfurls a few tricks and some weighted dialogue. "Deception requires complicity," he says to Margaret. "We want to be deceived." Double-meaning alert! Then Nucky's fat friend, Harry, blurts out that he's lost everything in — wait for it — a Ponzi scheme. As in, the original Ponzi scheme. Belle, his concubine, quickly dumps him, and later petitions Nucky for money in exchange for some loving kindness, a conversation Margaret conveniently overhears.

Thus Margaret and Nucky's relationship, already fraying, finally shreds apart. Margaret asks, "Must I accept what you tell me and ask nothing more?" and Nucky spits at her, "A good person wouldn't be here right now" — perhaps talking about himself as much as her.

Also, Nucky tacitly acknowledges that he and Eli killed her husband — "I wanted to hurt her," Nucky says later, to Eli, who holds up his fists and shouts, "That's what these are for!" Eli, for once, has Nucky's number, suggesting he kept Margaret around because "she'll absolve you of all the sinful shit on your hands." Margaret, however, has now become a major liabilit — especially so once she packs up, slips her own straitjacket, and moves out of the gilded cage in which Nucky had stashed her.

Corrupt Agent Sepso, meanwhile, is getting antsy, so Nucky sends him off in search of a still. He and Van Alden find instead a baptismal service in a river. Now, if you are like us, the minute you saw (a) Van Alden, (b) Sepso and (c) water, you figured out where this was headed.

Yet the show teased it all out in an implausible way — why, for example, would Sepso agree to head back to the river a second time with nutcase Van Alden, but then resist going into the water itself? Sepso had said, "What do I have to do" to convince Van Alden to trust him, but still, this scene played oddly, as though it happened because it had to happen, not because it flowed naturally from the characters. We still can't figure out why Sepso didn't just take his transfer and hightail it to Detroit.

But he didn't, and now he's a goner. Michael Shannon's face in this scene suggested that he didn't mean to kill Sepso, but simply cleanse him; either way, he's got a dead body to account for now. We're having trouble imagining how Van Alden talks his way out of this, and are thinking that, one way or another, in next week's season finale, Van Alden will meet his maker. We just wonder whom he'll take along with him.

As for Jimmy: Angela's plot to slip away to Paris is foiled, as Mary (somewhat inexplicably) decides to decamp with her husband. We're just going to say it: We’ve never been invested in Angela or her story line, so this "twist" fell flat. We just wish she'd jump on a train, boat, or carriage and be gone. Instead, when she returns home, Jimmy somewhat ominously talks to his son of a future where "it'll just be us boys." So this would probably be a good time to start packing those paints and make a run for it. We've already seen what happens to people who stick around too long.

The other development, of course, is Jimmy's acknowledgment as the Commodore's heir. Interestingly, he tells Gillian he doesn't care if she poisons the Commodore, yet in a subsequent scene, he says his father's going to live after all; clearly, he and his mother have decided the Commodore is more useful to them alive than dead, at least for now.

And Nucky, unraveling, throws Eli under the bus, nominating Halloran for sheriff. Given that Halloran is a total idiot and Eli, for all his fraternal chafing, is Nucky's one true ally, we can't imagine this decision will play out well for the Nuck. In fact, Nucky, the glad-handing king of the circus, now finds himself suddenly and shockingly alone.

All in all, this was a good, if not great, episode: We don’t much care about Angela, and we're not onboard the Van Alden express train to damnation. We did, however, love the fight between Nucky and Margaret, the fight between Nucky and Eli, and every second of Harrow. Also: Hardeen!

So: What do you expect for next week's season finale? Maybe Margaret runs off with Van Alden? Or maybe, pregnant, she returns to Nucky's arms? Maybe Chalky shows up with an Uzi he just invented and blows everyone away, then smokes a cigarillo?

We have to imagine (hope!) that next week we'll see return visits from Chalky and Capone. (Remember when Rothstein's lawyer asked him if there's anyone in Chicago who might help him? We see an alliance in the offing.) We can't feel confident of the continued prospects of Van Alden, Angela, or anyone with the last name D'Alessio. And we suspect that Jimmy, and Harrow, will make a major move toward fulfilling the Commodore's prophecy about who exactly will be running this empire, and what exactly running it now requires.