D'Nesh was an Orion slave girl who, along with her sisters Navaar and Maras, were given to Captain Jonathan Archer by Harrad-Sar as a present to celebrate a trade agreement with the Orion Syndicate.
D'Nesh and her sisters exposed Enterprise NX-01 to a very potent pheromone that put all the men on the ship in a state of aggression that caused delusions. D'Nesh went to engineering, and received a tour from Commander Kelby.
Later, she seduced Kelby and convinced him to sabotage Enterprise's engines and attack his superior officer, Commander Tucker. Shortly thereafter, D'Nesh managed to persuade Lieutenant Reed to help arrest Commander T'Pol.
This was part of a plot to disable Enterprise and capture Archer so that he could be turned over to the Orion Syndicate. (ENT: "Bound")
