Rejal was sent to Deep Space 9 in 2371 to assist the Federation with their plans to install a subspace relay with which to communicate with the Gamma Quadrant. She was accompanied to the station by an academic associate, Ulani Belor. Shortly afterward, they were joined by an operative of the Obsidian Order, Dejar, who posed as another associate.
During her work on Deep Space 9 with Chief O'Brien, she was initially irritated by his offers and interest in helping with the modifications required for the project. She repeatedly dismissed him and insultingly questioned the modifications made to the station since the Bajoran Occupation. After being confronted by O'Brien regarding what he perceived to be her speciesism towards the engineering competency of Humans, he was rebuffed upon discovering that her annoyance with him was not as a result of his species, but that he was male – apparently the Cardassian male is stereotyped by his engineering incompetence. After being chided by O'Brien, she discovered that this stereotype was not applicable to the Human male, especially upon learning of the chief's position and observing his exceptional skill.
While working to complete the modifications at a later time, Gilora made advances on O'Brien based on his confrontational attitude, that being the "flirtations" of the typical Cardassian male. Uncomfortable and bothered by her actions (particularly her offer to bear "many healthy children"), O'Brien related to her that he already had a healthy child and a wife. Embarrassed that she had misinterpreted his irritability as a result of a "cross-cultural misunderstanding" and by O'Brien's declaration that he was not remotely interested in her, Gilora left the chief to finish the work alone.
Later during the mission, while in the Gamma Quadrant, Gilora exposed Dejar's undercover status (as an Obsidian Order operative) on board the USS Defiant, to ensure that Dejar's sabotage was not left attributed to a mistake of O'Brien's. Gilora explained this to O'Brien upon her departure from DS9 to show her appreciation for his skill as an engineer. He in turn appreciated Gilora's courage. Before leaving the station, she told him that his wife was a lucky woman and gave him a kiss on the cheek. (DS9: "Destiny")