This episode contains a very, very subtle condemnation of the Cardassian justice system. See, when a crime is committed on Cardassia, the Cardassian police do a quick search before moving on to "interrogating" potential witnesses, and if those witnesses don't admit to seeing anything then they're charged with the crime and found guilty. But on Earth, we send in teams of attractive, wise-cracking detectives to thoroughly investigate crime scenes and uncover the most minute pieces of evidence imaginable. Then we make very accurate police-procedural shows based on the work of real detectives. That's how Sisko knew to look for the reflection of the obelisk in the waterfall, then pull the old zoom/flip/enhance trick, because he saw it on an episode of CSI: Tycho City. That's why the Cardassians failed to find B'hala during the occupation of Bajor, their cop shows just aren't up to our standard.
This episode is something of a mixed bag. As a mythology episode it's pretty great, this is the strongest foreshadowing that DS9 has ever done and all of it matters. We get references to an upcoming war with the Dominion, a "swarm of locusts" heading to Cardassia, and a revelation that Bajor must stand alone to survive a coming calamity. All of this material comes to pass before the season ends, the locusts represent the Dominion, the conflict between the Federation and the Dominion will soon appear inevitable, and Bajor's independence allows them to survive the war unscathed. For DS9, this level of foreshadowing is damn impressive, and it's arguably the best use of the Prophet's non-linearity in the show, they manipulated events from a distance without taking control of anybody and shooting beams of light from their chest.
As a standalone episode, there are a number of things "off" about the story. The episode begins with Sisko being P for Picarded
, and suddenly he's having visions of the future. Compared to some other plots on Star Trek it's not so outlandish, especially considering Sisko is the Emissary, it just comes across as rather convenient. The Federation's decision to allow Bajor to join their exclusive club comes completely out of the blue. You can't just drop such a major plot-point into an episode like this, it has to be built up to in previous episodes and it just wasn't. Where's First Minister Shakaar during all this? One of the biggest moments in Bajoran history and their political leader is absent?
It's a pretty good episode, it's an important episode, but there are too many issues with the plot for me to consider it a great one.