A ship with an ill person docks with the station. Kira says the only known cases of Kalla-Nohra she knows of were the result of a mining accident at a Bajoran labour camp. The patient turns out to be Cardassian. Instant conflict! Just add guns!
The Cardassian makes a run for it, but Odo makes the intercept. Kira accuses him of being a war criminal, and he's promptly bundled into the cells. Odo says Marritza isn't on any of the wanted lists, but Kira insists he must have been at the labour camp and starts ranting about how bad the conditions were there. Sisko goes to chat to Marritza, who insists he has a different disease with similar symptoms. So Sisko talks to Bashir who insists Marritza has Kalla-Nohra. Then the Bajorans ring up and ask about the Cardassian. Sisko's day just became infinitely more complicated.
Sisko tells Kira he's putting Odo in charge of finding out if Marritza *is* a war criminal but she gives him puppy dog eyes until he turns the investigation over to her. Kira goes to security to check on Odo's progress and "question" the prisoner. Marritza confesses he was a filing clerk at the labour camp and the reports of conditions there were exaggerated to kept the other Bajorans fearful.
Meanwhile, the other Cardassians ring Sisko up to ask why Marritza's being detained. Veiled threats are swapped. Etc.
They get a picture of Marritza from the archives and... it doesn't match the prisoner. They look at the other people in the picture and determine he's Gul Darhe'el - the man in charge of the labour camp. Marritza cheerfully boasts about his work to Kira.
This episode has been pleasingly Quark-free so far, I must say.
Odo wonders how Marritza knew which resistance cell she was in, so she goes to take some more abuse from the prisoner. Some of the labour camp survivors pop up to the station and, oh crap, there's Quark. Odo asks Bashir about a communication from ages ago linking Kira and Marritza, then rings up Gul Dukat, who says Gul Darhe'el is dead and buried. Odo talks him into getting access to the Cardassian files.
Meanwhile, Kira takes more abuse from the prisoner, until Odo turns up to tell her that the prisoner wanted to be caught. Also Darhe'el is dead. Kira refuses to believe the evidence from the Cardassians. Bashir reveals the prisoner has had cosmetic surgery in order to look like Darhe'el. Kira questions the prisoner some more and confronts him over the fact he's actually Marritza and not Darhe'el whereapon he breaks down and reveals he was a sissy all through the occupation and cowered under his bunk at nights. Kira takes pity on him and lets him go.
Then later on, he's stabbed by a Bajoran and dies. Oh well!