Wex was an identity taken by Odo in 2376 during his quest to locate the missing Bajoran Kai, Opaka Sulan and learn more about the Ascendants. Odo took the form of a Trelian female and tracked down Opaka on the planet Ee. Odo then travelled with Opaka and Jake Sisko to the Idran system and then to the Alpha Quadrant and Deep Space 9. (DS9 novels: Rising Son, Unity)