Nutshell: Not perfect, but quite good. This show certainly shatters the status quo rather nicely.
To successfully and plausibly resolve the behemoth of a plot that was "In Purgatory's Shadow" is a tall order, to be sure. "By Inferno's Light" does it well. Not perfectly, perhaps—part one of this story is clearly stronger than this half is, both in style and character—but there are so many interesting consequences and developments to come out of "Inferno" that the show works very nicely.
If there's one thing that this episode proves, it's that major storylines on DS9 never simply go away or get resolved. Rather, they undergo metamorphoses and become twisted into labyrinthine webs of political intrigue. In a big way, I like that. It seems that anything is possible, because it's hard to know who will be on whose side from one month to the next. Still, at the same time, it's a tad frustrating to have so many threads hanging around and entangling each other with no resolution in sight. A tad frustrating, perhaps, but also very interesting.
As the Dominion enters the Alpha Quadrant, they cast a brief, intimidating stare in DS9's direction and then turn straight for Cardassia. (Note: This seems very consistent with Sisko's vision in "Rapture" of locusts that were to go to Cardassia first before "destroying Bajor unless it stands alone." Quite interesting.) The big surprise of the episode: Gul Dukat is joining them to escort them to Cardassia.
You see, Cardassia is joining the Dominion.
And I thought the revelations in part one were unpredictable.
As radical as this shocking notion is, it makes perfect sense when looking at all the past material. Dukat hates the Klingons for what they've done, he hates Cardassia's current state of paralysis, he hates the Maquis, and he fears the Dominion. With one swift stroke (after months of secret negotiation between Cardassia and the Dominion) Dukat's solution will make Cardassia strong, force the Klingons to leave, force the Maquis to abandon their colonies in Cardassian space, and make allies out of the biggest threat of all.
That, my friends, is one hell of a package deal, and it changes nearly everything on the series.
Before I continue discussing the implications of this event, I'll first discuss the plot at hand, because there are quite a few plot-based issues set up in "Purgatory" that "Inferno" obviously had to put to rest—and for the most part, the plot pulled itself together fairly well.
While Sisko & Co. is dealing with the home front, Worf, Garak, and Bashir begin devising an escape plan. They hope to use Tain's rigged communication device in the wall panel of their cell to contact the Runabout for a beam-out. I wouldn't call this plot spectacular or imaginative as these things go, but the way Behr and Wolfe's teleplay handles the details is commendable.
One notion worthy of praise is the way the different prisoners share a common interest and a common enemy. Outside a Dominion facility it seems likely that these different people—Romulans, Klingons, Cardassians, humans, and Breen—would not be on the best of terms given the political situations between their respective homelands. But under the Dominion's thumb, they easily put aside their differences to accomplish a common goal. The plan is a team project that effectively displays everyone keeping composure under high pressure.
Garak in particular has to cope with the pressure. He's the only one with the technical knowledge, and even he has limited skills. He has to quietly and quickly work inside a small, dark, hot, enclosed area of space. And on top of that, he's claustrophobic.
Meanwhile, Worf is forced to fight Jem'Hadar soldiers in hand-to-hand combat "tournaments" that progress in difficulty from one match to the next. Worf's part of the story is nothing that hasn't been done before, but I'm still convinced that Michael Dorn and the writers have a firm grip on Worf as a character, and everything that happens here is in tune with that.
Naturally, the events back at DS9 are what demand more attention. With a shapeshifter roaming the station, Starfleet dispatching ships to the area, and Dukat making threats directly to Sisko (demanding Bajor and the Federation return the station to Cardassia or else the Dominion will destroy it), the plot truly feels like a countdown to Armageddon. The entire episode crescendos with increasing tension and suspense to what promises to be a final confrontation.
And the entire Alpha Quadrant seems to be involved. The Dominion promptly drives the Klingon presence out of Cardassian space, at which point the Klingons fall back to DS9. Sisko wisely takes advantage of the situation, asking Gowron to consider revitalizing the Khitomer Accords—the Klingon/Federation peace treaty. (Gowron's words aptly reveal how sweeping changes like these can come so swiftly unexpectedly: "Five years ago no one had ever heard of Bajor or Deep Space Nine. Now all our hopes rest here. Where the tides of fortune take us no man will know.")
The episode drops another surprise upon us when a group of Romulan ships decloaks, requesting to join the fleet. Again, this is an interesting example of different groups putting aside their differences to benefit the larger picture. I found myself saying aloud "United we stand, divided we fall" at this point in the show, because it fit the circumstances so well. Sure, that may sound like a bit of a cliche, but it is a compelling—and also true—ideal. The idea of the entire Alpha Quadrant making a stand against the Dominion is something that I would suppose even the Dominion might have second thoughts about. It also makes Dukat look like the lone sell-out of the lot. (Sisko even flat-out tells Dukat that he has "sold out his people to the Dominion." Dukat merely retorts that he has made Cardassia strong again.)
Dukat's actions speak for themselves. They virtually completely turn the character around from someone we could sympathize with earlier in the season (the Dukat who was fighting the Klingons in the name of Cardassia) back into an opportunist who is more interested in pure strength for Cardassia than freedom or independence. (I'm very intrigued at how exactly Cardassia will operate under Dominion rule.)
Like Kira said to Ziyal in part one, you can only judge a person for their actions, and Dukat's actions speak the words of a coward and an opportunist. Instead of standing against the Dominion with the rest of the Alpha Quadrant, Dukat has made a bad situation potentially worse for possibly everyone (I can't imagine that everyone on Cardassia supports being run by the Dominion). He even disowns his daughter and accepts that she will die with everyone else on DS9. He may as well have sold his soul, as far as I'm concerned.
But that's the point, isn't it? To make Dukat a bad guy again and reinstate some of the "edge" he used to have before he became more sympathetic. It certainly works. From here on (unless, of course, something equally impacting happens concerning Cardassia) I can't imagine ever seeing Dukat in a situation that's not confrontational.
By the same token, suddenly the Klingons are back on "our" side (Gowron signs the treaty), and even the Romulans look less menacing and more reasonable than before. What's so compelling about the myriad of agreements is to look back and see how intertwined different events caused different groups to take the sides they did. Everything here is connected if you trace the plot lines, and I find that fascinating. A year and a half ago the Federation condemned the Klingons because they invaded Cardassian space. Now the Klingons come back to the Federation because the Cardassians (a subset of which tried to destroy the Dominion two years ago, by the way) have joined the Dominion and threaten to destroy the Klingons.
These large-scale events are compelling, and the build up of the whole episode to a final-act event is good edge-of-seat suspense. Unfortunately, the ending of "Inferno" is less than I had hoped given the two hours of setup. It works absolutely wonderfully when you consider the long-term implications and future shows, but something about the actual events of the finale isn't quite right.
I think the problem is that it tries to compact the climax into five minutes of air time. The ending feels a bit... rushed. The whole chess game turns out to be pivoting on one Changeling infiltrator assigned to execute the Master Plan. But in order for the Changeling to be exposed, the real Bashir has to escape from the Dominion prison and warn the station. Naturally, Bashir and his party escapes at the very last second—nicely executed for a "close call" countdown, but awfully convenient if you think about it. (Why, for example, would the Runabout still be orbiting the prison facility? Are the Jem'Hadar that stupid?) Meanwhile, the colossal, imminent attack by the Dominion turns out to be a ruse to hide the Bashir-Changeling's true mission—to trigger the supernova of Bajor's star, destroying Bajor, DS9, and half the Klingon, Romulan, and Starfleet fleets. Bashir's warning comes just in the nick of time, and Kira is able to stop the Runabout before it explodes.
Bashir's escape from prison works fairly well (even if the execution was a little abrupt), because the plot had, after all, spent a good part of the hour setting it up. Likewise, the Changeling's plan stands to reason under scrutiny. It certainly makes strategic sense that the Dominion would try to take out DS9 and half the fleet, as Sisko says, "without firing a single shot."
Still, I wish more time would've been spent on revealing the Changeling saboteur than on fight scenes between Worf and Jem'Hadar soldiers. Couldn't the shapeshifter have been discovered by the crew by means more interesting than Bashir's deus ex machina warning?
Also, the disappearance of the danger was just a little too abrupt for my tastes. Going from "Stop that Changeling at all costs!" to "Armageddon will have to wait for another day" to a quiet scene between Garak and Ziyal within barely two minutes of screen time brings down the sense of urgency and doom far too quickly and easily to make it feel genuine.
Such complaints about the plot are minor when considering the great developments this episode brings to the big picture. I like to see things happen, and in "By Inferno's Light" lots of things do happen. Sure, the violent confrontation that seemed imminent a week ago and inevitable for two and a half years may have been averted, but there are so many changes in the overall storyline that the situation is more perverted than probably could've been imagined. This is what makes DS9 so riveting as a series. It's unpredictable on such a large scale. Yet what appears to be a huge political mess has rational reasons for taking place. I'm extremely interested in seeing what will happen next.