Dax is nearly kidnapped, the ship absconding with her caught by a tractor beam at the last moment. However, her kidnappers turn out to have been executing a warrant for her arrest and extradition to Klaestron IV, for the crimes of treason and the murder of Ardelon Tandro, a military hero.
Dax refuses to defend herself, but Sisko wrangles her an extradition hearing by pointing out that the station is technically Bajoran territory, and there is no extradition treaty between Bajor and Klaestron IV. So the episode proceeds as a courtroom drama, with the central mystery: did Curzon Dax betray and kill his friend, thirty years ago? And is Jadzia culpable for it, if so?
The good: we get our first real look at the Trill, as they will be portrayed in DS9. What we saw in TNG's The Host was quite different, and much less interesting. Anne Haney's portrayal of the Bajoran arbiter, Els Renora, was also excellent, as was Gregory Itzin's portrayal of Ilon Tandro.
The bad: for an episode centered on Dax, we don't really get to see much from Dax, herself. Throughout, Terry Farrell is given the terribly difficult job of standing around, staring blankly, saying what amounts to "I'm sorry Benjamin, I'm afraid I can't do that." Even when she's being kidnapped, her protests are very... unenthusiastic. To be fair, she's probably trying to convey disorientation, but it's disappointing, overall. Things will get better, eventually.
Bashir, too, isn't treated well. Dax ignores him through a cup of Klingon coffee and heads off to get kidnapped, and he heroically gets himself knocked out while attempting to badger her on her way back to her quarters. Avery Brooks (and a brief appearance by Armin Shimerman) aside, none of the regulars give terribly good performances, nor have terribly interesting roles.
This is inferior to The Measure of a Man, which had more interesting argumentation in the courtroom, but the concept is solid, and the moral question is interesting. Tandro's argument isn't bulletproof, but it is powerful:
The real point is that Commander Sisko would have you endorse his idea of a perfect Trill crime. To commit it, all one has to do is elude capture long enough to change hosts, and then he or she can go free.
If there were a murderous Trill symbiont, taking advantage of the ability to switch bodies to escape punishment, what would be the just response? Or if it were the host who were more responsible for the crime, how would that change things? I don't hold with Tandro's idea that if Jadzia is capable of feeling the guilt for a crime, then she should be held morally and legally culpable for it, but there must be some appropriate response.
And that is a major weakness of the episode: there must be some appropriate response, and the Trill would have decided what it is, long ago. If Sisko were interested in upholding Federation principles, then probably he should have consulted with the Trill government to learn how they handle situations like this. He did send Kira off to do research along those lines, but we didn't see any results from it--perhaps the implication being that the Trill would consider the extradition just? Anyway, Sisko's "I knew the man" is not a compelling argument. We will get another look at this in a future episode, at least.