The DS9 team identify an ill stranger as a Cardassian war criminal, inciting complicated feelings in Kira and Bajor; they work to avoid interstellar incident as they examine the mysteries surrounding his arrival on Deep Space Nine.
Kira's journey continues to a new rung on the spiral she's been climbing through the past several episodes. Throughout the first season she has, again and again, had to confront her inner fears and demons. Maybe more than any other character in the season, she's had tangible loss and change. She has had to get to the point of becoming a political ally of the Federation, which she distrusts; she's had to reject the more extreme fringe of the societies which had got her through the war, Kai Opaka began Kira on a quest to confront those demons, and Kira finally began to seriously let go of the past in "Progress" when she encouraged Bajoran refugees to give up their resistance. Here, she plunges even more deeply into the chips on her own shoulder.
Aamin Marritza is a simple filing clerk with a disease unique to Gallitep, the location of several war crimes committed by the Cardassians under the leadership of Gul Darhe'el. While confirming Marritza's identity, a photo comes to light identifying him as Darheel. Bajor and Kira push for his transfer to Bajoran authority and certain execution, nearly inciting a war with Cardassia. It turns out Darhe'el is a fake and Marritza is actually the prisoner's true identity; he's working out intense guilt over the death of Bajorans. Accepting the truth of Marritza's feelings brings out some very intense sympathetic and empathetic responses from Kira herself - but before Marritza is truly freed, he's killed by a Bajoran dissident simply for being Cardassian.
The titular "Duet" is an amusing puzzle. Does it refer to the dual nature of Marritza/Darhe'el? Or the dialogue between Marritza and Kira? I think, after two watchings of the ep, the changes in Marritza echo in a small scale many of the changes in Kira herself. Whatever side of the war you're on, there's always going to be a struggle to recovery. It was a pleasure though to see the developing layers of trust between Kira, Sisko and Odo.
Bits and pieces
Harris Yulin, who plays Marritza, seems to have a preference for playing dramatic roles; he shows up again years later on Buffy the Vampire Slayer as Quentin Travers. He does an excellent job here as Marritza; you can believe the character's capable of orchestrating a covered-up death - and more.
This episode made me see parallels between Kira and G'Kar, and wondering how far Kira's experiences are going to take her in terms of emotional and spiritual depth. Visitor really brought this character to a new level.
The final scene seemed almost melodramatic to me in composition - making Marritza almost Christ-like in a way. Very touching and well done.
Kira: You think this is all some personal vendetta on my part, don't you?
Sisko: I think you're too close to be objective, yes.
Kira: You're right, I'm not objective. But I'm your first officer, and I give you my word I will conduct myself accordingly. You once said we were friends. I'm asking you now as a friend, please, let me conduct this investigation. I owe it to them.
Sisko: You mean the victims.
Kira: That's right. The ones who moved too slowly and never moved again. I'm asking for all the Bajorans who can't ask. Let a Bajoran do this.
Kira: That's just it. I don't want him to be a file clerk. I want him to be, I don't know, something worse.
Dax: You want him to be guilty.
Kira: As far as I'm concerned, if he was at Gallitep, he is guilty. They're all guilty. His punishment will let Bajor feel some satisfaction.
Dax: It sounds like you're trying too hard to believe what you're saying. You already know if you punish him without reason, it won't mean anything. And you already know vengeance isn't enough.
Four out of four dermal regenerators.