In Quark's, Odo meets a beautiful woman named Arissa and is impressed by her powers of observation. Later, he is surprised when the same woman is arrested for trying to break into the station's computer. Odo questions her about the man she was waiting for in Quark's - an Idanian named Tauvid Rem. Arissa tells Odo Tauvid has information about the daughter she gave up fifteen years before. Odo takes her to Tauvid's quarters, where they discover he has been killed.
Soon afterward, Odo catches Arissa retrieving a datacrystal Tauvid hid. She admits to Odo that she doesn't really have a daughter, and tells him that she came to meet with Tauvid because she wants to escape working for the Orion Syndicate - a notorious criminal organization. Her boss, a man named Draim, probably had Tauvid killed to keep her from getting the unknown information contained in the crystal.
Odo hides Arissa in his quarters as he begins an investigation, while Dax and O'Brien attempt to access the heavily protected datacrystal. Arissa tells Odo how she began to work for Draim, only to want out when she learned the deadly consequences her assignments meant for others. Odo encourages her to testify against Draim and take back her life. That night, he returns to his quarters, where the two of them give in to their growing attraction to each other.
After spending a passionate night with Odo, Arissa sends a message to Draim proposing an exchange - the crystal for her life. Draim agrees, but instructs his hit men, Traidy and Sorm, to kill her after the crystal is retrieved. Meanwhile, an Idanian official arrives, informing Odo that Arissa is not who she appears to be, but actually an Idanian agent given a new identity in order to infiltrate Draim's organization. Even Arissa does not know this, since her memory has been erased. The crystal contains all of her real memories. The Idanian asks to be taken to Arissa, and Odo quickly complies - only to find both the woman and the crystal missing.
Arissa prepares to give Traidy the Crystal in exchange for her life. But just as he and Sorm try to ambush her, Odo and the Idanian save Arissa. Later, her memories and true appearance are restored. She and Odo then meet one last, painful time, after which Arissa returns to her married life - and Odo is left brokenhearted.