- For the regular universe counterpart, see Jadzia Dax.
In 2369, Jadzia was working as a mercenary captain of her own ship, the Rogue Star. A frequent client of hers was Annika Hansen, who took passage on the Rogue Star on several missions for the Obsidian Order, although her ties to the Order were unknown to Jadzia. A staple of Jadzia's outfit at this time was a curved blade that she always had at her waist. (ST novel: Dark Passions, Book One)
By 2371, she was romantically involved with Benjamin Sisko's mirror counterpart; after his "death", she became involved with Julian Bashir's mirror counterpart. In 2371, Chakotay's mirror counterpart described her as having "good looks but no personality." (VOY novel: The Mirror-Scaled Serpent)
Sometime, around 2374, Dax partook in a seek-and-destrroy recon mission to assassinate the Mirror Universe counterpart of Sela. But the meleé was briefly witnessed, and the outcome as to whether or not she succeeded is unknown. (TNG novel: I, Q)
Jadzia was killed in 2375 in a skirmish with Alliance troops. Julian Bashir's mirror counterpart took the loss very hard. (DS9 episode: The Emperor's New Cloak) Later that year, Bashir was given command of a starship, which he named the Jadzia. (DS9 novel: Saturn's Children)