"What are you two staring at?"
- - Bareil Antos
In 2374, Bareil was sent into the mirror universe's Deep Space 9 by Alliance Intendant Kira Nerys, using a multidimensional transporter device. At first, he took the Intendant's counterpart, Major Kira, hostage after he arriving at Deep Space 9's Ops. He proceeded to attempt to escape the station, but he soon released her and stopped his escape attempt, when Major Kira informed him that his disruptor was not working. In the days after, they quickly became attracted to each other and had a brief romance. During this time, Bareil also had an experience with the Orb of Prophecy and Change, which he claimed he wanted as way of exploring his spirituality.
His true objective though, was to steal the Orb, which he and the Intendant hoped to use to unite his Bajor against the Klingon-Cardassian Alliance. His lover, Intendant Kira Nerys, soon joined him in the mirror universe and encouraged to continue with their plan. However, at the last minute, Bareil stunned her and her and himself back to this universe, minus the Orb.
During his visit to the mirror universe, many Bajorans there stared at him because he had a striking resemblance to his mirror universe counterpart, the late Vedek Bareil.
During his time on Deep Space 9, Bareil claim that he had once lived in Dahkur Province and meet a woman there. (DS9: "Resurrection") Bariel was later mentioned by Intendant Kira as having joined the Terran Rebellion full-time, presumably inspired by Major Kira to fight for something worth dying for.