Odo and Eddington come to Captain Sisko with evidence that Kasidy Yates is smuggling for the Maquis. Though Sisko is initially dismissive of the idea, doubt begins to creep in as Kasidy's actions grow ever more suspicious. And with an important shipment of equipment to the Cardassians soon coming through the station, they need to uncover the truth fast. Meanwhile, Dukat's daughter, Tora Ziyal, reaches out to Garak. But her motives are unclear, and Garak's natural sense of caution is at odds with his curiosity.
"For the Cause" is a case where an episode's original inspiration bore little resemblance to the finished product. Freelance writer Mark Gehred-O'Connell pitched a premise sparked by the Oklahoma City bombing, a "the perpetrator isn't who you'd expect" tale that morphed a lot as the staff writers took over and Ronald D. Moore crafted the script. The desire to challenge Sisko's relationship with Kasidy was brought into the mix, as was the desire to do something surprising with the character of Eddington -- who many fans had expected would be revealed eventually as a changeling infiltrator.
It's a well-executed story arc. We see the domestic bliss of Ben and Kasidy right at the top of the episode -- waking up in bed together with playful banter. We see Sisko's reflexive, full-throated defense of her gradually give way to creeping doubt. We see escalating efforts by Sisko to catch Kasidy in a lie. And most achingly, in the end, we see his last-ditch effort (in a sort of code) to talk her away from her criminal path. The series has invested in this relationship, and is able to use that now to great effect.
While the nature of the story hides much of Kasidy's thinking from the audience, it's a strong episode for her too. She smoothly deflects so many tests of her loyalties, but can't help but dig herself deeper and deeper. She ultimately has a reason for her actions that feels sympathetic. And she's willing to face responsibility herself, on behalf of her crew. She could flee, but she really does care about Sisko. This is not a plot line constructed to rid the star of a TV show of an unwanted, ongoing romantic relationship. This is a test of that relationship that the couple is meant to survive -- and when she says "I'll be back" (and he replies "I'll be here"), we believe it.
All this drama rather effectively masks the ultimate reveal of Eddington as a traitor, on a mission so important to the Maquis that they're willing to burn two embedded operatives to complete it. His betrayal is quite personal to Sisko on at least two levels: that Eddington was explicitly given "just one more chance" to redeem himself from a past betrayal, and that the motivations he claims in the end cut so deeply. He says that the real offense of the Maquis is that the they don't want to be a part of the Federation. But when he compares them to the Borg, those responsible for the death of Sisko's wife? That is an insult that cannot be brooked. And this vendetta is another thread the show will continue in the future.
Far less effective, though, is the Garak/Ziyal storyline. Part of the awkwardness is in the way it's told: it's definitely Ziyal driving the story here -- she's the one reaching out to Garak. But the story is told from Garak's point of view, as he rather passively tries to suss out her intentions. And ultimately, it's not terribly interesting whether she's seeking chaste companionship or expressing romantic interest... because it truly had better not be the latter.
Even considering this episode in the time it was made (rather than through a modern lens), the age difference here (specifically, Ziyal's youth) makes a romance here a troubling prospect. Ziyal is recast here since her previous appearance, possibly to make this seem less icky, but there are still some subtextual Lolita vibes at play here. Or, at least... it seems like there might be? According to show runner Ira Steven Behr, the writers had decided fairly early on to write Garak as implicitly gay (though they never had the courage to make this explicit). Actor Andrew Robinson had been shading the performance that way too, after an initial instinct to play a wider, more inclusive sexuality. In any case, it's not doing much of a service for the character to put him in this storyline -- neither in regards to his sexuality, nor in seeing his master spy's instincts so flummoxed by one young woman.
Other observations:
- While Kira isn't a major character in this story, her past as a terrorist is mentioned in a compelling discussion between Worf, O'Brien, and Eddington. It's nice to have this reminder of Kira's hard history -- and also nice that she expresses frustration at the way the Federation is helping the Cardassians to a greater extent than they helped the Bajorans.
- The little bit we see of the game of springball looks pretty good. They spent some time to film it convincingly.
- Sisko's relationships are important throughout the episode -- and not just with Kasidy Yates. He specifically voices to Jake how important their relationship is to him. And his closest friend Dax takes an unsuccessful stab at "bright siding" Kasidy's betrayal, saying it could have been worse. Underscoring what Sisko has lost by the end of the episode, the final shot shows him small in frame, in a big, empty cargo bay.
- There's a fun little mention of using the holosuite to make two different baseball teams from different time periods play each other. That's totally the sort of thing people would use a holosuite for. (Besides porn.)