"Past Prologue" is the second Star Trek: Deep Space Nine episode aired (third produced, which is why it's listed as "episode 4" in the database), right after "The Emissary". Thus, its purpose is to grab those people who were fascinated by the premiere and keep them coming back week after week. Sometimes, the first "regular" show after a premiere is even more important, because it has to demonstrate that the producers of the show are going to be able to consistently bring the same quality to the show as the premiere had, despite not having quite the same lead time (some premieres are in development for years).
"Past Prologue" does a wonderful job of that, showcasing one of the new alien characters, Kira Nerys (Nana Visitor) and giving us even more of her background. We already know that Kira spent some time in the Bajoran Resistance fighting the Cardassians, but not a lot of detail was given in "The Emissary." This episode goes into great detail, however, also giving us an even stronger sense of her personality. The writing is sharp and the acting is generally top notch. It also introduces the wonderful Garak ("plain, simple Garak"), a Cardassian tailor who stayed on the station, and one who would quickly become a favourite recurring character on the series.
The episode opens with Dr. Bashir (Siddig El Fadil) having a pleasant lunch in the Replimat (basically, the food court of the station) when Garak (Andrew Robinson) approaches him and strikes up a conversation. It seems that Garak is the only Cardassian left on the station, and some people believe that he's the eyes and ears of the Cardassian government. Bashir quickly reports the conversation to Sisko (Avery Brooks) and the rest of the command crew, excited but also apprehensive about being approached by a potential spy. Sisko tries to assuage his fears, but is interrupted by a Bajoran ship appearing in the system, being hounded by a Cardassian ship. The Bajoran in question, Tahna Los (Jeffrey Nordling), requests asylum on the station. Gul Danar (Vaughn Armstrong) demands that he be turned over immediately, for crimes against the Cardassian Empire. Sisko has to consider the request, but ultimately decides against turning him over because it would harm relations with the Bajoran Provisional Government.
Tahna is a member of the Kon Ma, a fanatical Bajoran resistance movement that some say hasn't stopped fighting despite the fact that Cardassia has withdrawn from Bajor. Has he given up his ties to the organization? Or has the organization given up the fight and agreed to live in peace with the rest of the Bajorans? And what are Lursa (Barbara March) and B'Etor (Gwynyth Walsh), two Klingon renegades from Star Trek: The Next Generation, doing lurking around the station? The answer to all these questions will force Kira to make a decision and to face her past.
Secondly, Tahna is being chased for stealing a warp converter from the Cardassians. It's strongly implied that he was jumped by them almost immediately after stealing it. Something in this explanation stinks, because if this is true, one of two things would have happened: 1) it would have been destroyed when his ship was destroyed (and thus we have no episode), or 2) he would have had it with him when he beamed aboard (and again, we would have no episode). Yet again, a major logic hole defeats a television episode.
Despite all that, this episode wonderfully gets past its fairly pedestrian plot. It does this by emphasizing Deep Space Nine's best aspect: characterization. There are so many gems in this episode, that I can't really mention them all. The first is obviously Garak and Bashir. Bashir further demonstrates that he's quite naïve, and that brilliance doesn't necessarily mean that you are the best at every situation. Garak leads him around by the nose as he exposes the plot and hints at Cardassia's interest in the whole thing. The dialogue between these two is wonderful and there is great chemistry between the two actors. (As an aside, when I first saw most of this series, I had not seen the first Dirty Harry movie yet, where Andrew Robinson plays a psycho. After seeing the movie, I think I'm going to be looking at his portrayal of Garak in a whole new way)
Another thing "Past Prologue" does is expand Kira's relationship with Odo (Rene Auberjonois). The conversation they have in the security office as she decides what she should do is great, and Auberjonois plays it wonderfully, letting Kira talk out everything she needs to and then pointing her in the right direction: following her heart. His sedate "There's somebody down here in Security who wants to talk to you, Commander" at the end is beautifully done.
"Past Prologue" showed that the producers could keep going at the same level (if not better) as the premiere. It was a welcome boost to an already strong franchise. The ideas weren't as grand, but the execution was wonderful.
“Cardassian rule may have been oppressive, but at least it was… simple.” Odo
“Go over my head again, I’ll have yours on a platter.” Sisko to Kira after she talked to an admiral about Sisko's handling of the situation.