Starfleet officer Melora Pazlar (Daphne Ashbrook), an Elaysian whose species' physiology is incompatible with the strength of artificial gravity found on most humanoid communities including Deep Space Nine, arrives on the station. She must use external mechanical apparatus to exist comfortably on the station. Because of her physical condition, Melora is argumentative, even rude, in insisting that she not be shown any undue accommodation. Nevertheless, Doctor Julian Bashir (Alexander Siddig) sees through Melora's barriers and the two become romantically involved. Meanwhile, just as Quark (Armin Shimerman) is about to conclude a deal over some historical relics with a man named Ashrock (Don Stark), Fallit Kot (Peter Crombie) walks into his bar. The two have history, with Kot declaring to Quark that he is on DS9 to settle certain "debts". However, when questioned by Security Chief Odo (René Auberjonois), Kot denies any ill intentions toward the Ferengi.
Bashir develops a medical procedure that could allow Melora to comfortably walk without the help of any of the equipment she currently uses. Even after successfully participating in tests of Bashir's new engineering technique, Melora has misgivings. If she goes through with the procedure, she will no longer be able to live in the low-gravity environment of her home world. Lt. Jadzia Dax (Terry Farrell), during a survey mission with Melora to the Gamma Quadrant, compares her predicament to that of "The Little Mermaid". Kot attacks Quark in his quarters, but Quark offers him 199 bars of gold-pressed latinum in exchange for his life. Kot takes the deal, and they go to meet Ashrock at an airlock. Quark's deal is closed, but Kot shoots Ashrock and takes the relics in addition to the latinum. Kot forces the Ferengi to go with him, and they come across Melora and Dax, who are returning from their survey. Kot takes all three hostage aboard the runaboutOrinoco.
Commander Benjamin Sisko (Avery Brooks) orders the runabout to be held in a tractor beam. Kot demands they be released, shooting Melora to prove his point. Sisko lets them go, but takes Bashir and Chief Miles O'Brien (Colm Meaney) with him in the runabout Rio Grande. They pursue Orinoco through the Bajoran wormhole. Kot orders Dax to fire on the Rio Grande but as she refuses, she notices that Melora is not only still alive, but crawling toward a console controlling the ship's gravity. In her element after shutting down the gravity, Melora overpowers Kot, who is taken into custody. After finally deciding against going through with Julian's procedure, Melora and Julian enjoy the Klingon chef's (Ron Taylor) serenade at the restaurant where they had their first date.