The crew welcomes Ensign Melora Pazlar, a cartographer on a mission to chart the Gamma Quadrant. Melora is an Elaysian, a species from a planet with very low gravity, and because of this, she must use a wheelchair and braces to get around in "normal" conditions. Bashir has prepared the station with special ramps to give her access, but she makes it very clear that she does not need or want special treatment and hates being regarded as a person with a "problem." Meanwhile, Quark welcomes his own visitor, Fallit Kot, an old acquaintance who announces that he has come to the station to seek revenge against the Ferengi by killing him. Later, despite the obvious strain gravity puts on her, Melora meets with Sisko and tries to convince him to let her pilot a Runabout around the Gamma Quadrant on her own. Sisko is understanding, but insists that Dax accompany her, leaving Melora stung. Bashir then visits her in her quarters, which he has equipped with a special device that reduces gravity and lets her "fly" around. He asks her to join him for dinner, and she agrees.

Back at the bar, Quark prepares a sumptuous feast for Kot, but is unsuccessful in convincing his enemy to spare him. At the same time, Bashir and Melora enjoy their own meal, and the two begin to feel a strong attraction. Later, while preparing for her mission, Melora trips and falls in a doorway and is unable to get up. Dax finds her there and summons Bashir, then helps her to the infirmary. This incident has obviously humiliated Melora, but Bashir is understanding and reminds her that in space, everyone needs help now and then. This helps Melora feel comfortable with her new friend, so she turns down the gravity in her room and shows him how he can "fly" around with her. The two are soon caught up in the moment and share a passionate kiss.

On route to the Gamma Quadrant, Melora shares her concern over her feelings for Bashir with Dax. Dax encourages her to enjoy the romance rather than worry about any potential problems. Back at the station, a worried Quark tells Odo about Kot's plan to kill him — but this seems to please Odo more than it concerns him. Still, he promises to do his job. Later, Melora returns and seeks out Bashir, who has a surprise. He has been doing research on a neuromuscular adaptation theory that could possibly help her walk without a wheelchair, or her servo controls.

In the Infirmary, Bashir tries the new technology out on Melora, and is thrilled when she is suddenly able to lift her leg and is soon walking with just a little help from Bashir. Back in her quarters, he advises her not to use the low-gravity field actuator because it will "confuse" her motor cortex. She readily agrees to refrain, but, once he leaves, can't help missing her ability to fly. Meanwhile, Odo summons Fallit Kot to the security office and tells him that, while he sympathizes with his dislike of Quark, he cannot allow Kot to kill him. Kot feigns innocence, claiming that he never threatened Quark's life, but Odo later warns Quark to carry a combadge at all times and to be prepared to contact him. Sure enough, Kot appears in Quark's quarters that night and attacks him. Quark strikes a bargain for his life, offering Kot 199 bars of gold-press latinum he will receive through a trade with an alien named Ashrock.

The next day, Melora reveals to Bashir that she is feeling some apprehension about the fact that the effects of his treatment will soon be permanent. Not wanting to delude her, Bashir reminds her that she must give up her ability to fly if she wants to be able to walk. Meanwhile, Quark and Kot conduct their trade with Ashrock, after which Kot blasts Ashrock with a phaser and takes Quark hostage. They flee into a Runabout, trapping Dax and Melora inside, and Kot orders Dax to pilot the ship away from the station. Sisko, Kira, and O'Brien latch onto the Runabout with the tractor beam, but Kot responds by firing a phaser at Melora and knocking her to the floor, leaving her helpless. Moving fast, Sisko, O'Brien, and Bashir transport to another Runabout and Kira releases the tractor beam, letting Kot take off into the wormhole with the others in hot pursuit. Soon, Kot realizes he is being followed and orders Dax to fire on Sisko's ship. Before she can, Melora crawls across the floor unnoticed and reaches a switch that disengages the ship's gravity. Back in her "normal" state, she disables Kot, saving the day. Later, back at the station, she tells Bashir that she has decided against continuing the treatments. While he is obviously disappointed, he understands her decision, and is happy to simply be able to continue to get to know this remarkable woman.