A Kobheerian freighter requests permission to dock at Deep Space 9, stating that one of its passengers requires treatment for a condition known as Kalla-Nohra. Dr. Bashir is not familiar with the condition, but Major Kira recognizes it and informs Sisko that the only place to contract Kalla-Nohra was a mining accident at a particularly brutal labor camp called Gallitepp. As Kira helped liberate the camp at the end of the Cardassian occupation of Bajor, she asks to greet the passenger personally.
Upon arriving in Sickbay, Kira discovers that Bashir's new patient is not Bajoran but Cardassian. She has the man arrested as a war criminal, only to find his name, Aamin Marritza, is not listed for any crimes. Sisko sees no option but to let Marritza go, yet Kira is adamantâMarritza is Cardassian who was present at Gallitepp, she insists, which is reason enoughâand details the condition of the labor camp when she liberated it. Sisko decides to investigate further.
Further suspicions arise when Marritza claims he has never been to Bajor, an obvious lie as Bashir's medical test confirms that the man has Kalla-Nohra. Citing a conflict of interest, Sisko asks Kira to remove herself from the case, but her emotional plea convinces him to let her stay on it. When she interrogates Marritza, he claims that, while he did serve at Gallitepp, he was only a file clerk. He maintains the atrocities the Bajorans believe occurred at Gallitep were an illusion meant to keep other Bajorans in fear of the Cardassians.
An investigation corroborates Marritza's story, forcing Kira to cope with the possibility he may go free. A photograph from Gallitepp, however, reveals that the man being held is not Aamin Marritza but rather Gul Darhe'el, the "Butcher of Gallitepp" who reportedly murdered thousands of innocent Bajorans. The prisoner responds arrogantly when confronted with this information; not only does he admit he is Darhe'el, but he boasts that "My word, my every glance was law! And the verdict was always the same: guilty." Kira is visibly shaken.
As the episode progresses, Darhe'el lets slip the name of Kira's resistance cell during the occupation - information far too obscure for him to know. Other inconsistencies in his story begin to stand out, and the crew learns that "Darhe'el" has been disguising himself via cosmetic surgery - leading Kira to realize that the prisoner wanted not only to be caught but to be recognized as Darhe'el. Security chief Odo discovers that the real Darhe'el died five years prior and realizes the man he is holding is in fact Marritza, Darhe'el's clerk. Kira confronts the prisoner, whose guise begins to falter:
â I am alive. I will always be alive! It's Marritza who's dead! Marritza, who was good for nothing but cowering under his bunk and weeping like a woman. Who every night covered his ears because he couldn't bear to hear the screaming... for mercy... of the Bajorans... â
Marritza breaks down as he speaks, branding himself a coward. He begs Kira to prosecute him, insisting that Cardassia must be forced to admit its wrongdoings and that he is as guilty for remaining silent as Darhe'el was for committing the atrocities. Kira releases him, insisting that another murder is not the answer, but as Marritza is about to depart from the station, he is stabbed and killed by a drunken Bajoran. When Kira demands to know why, the Bajoran echoes her own earlier sentiment: being a Cardassian is reason enough. "No," Kira realizes, "it's not."