In the mirror universe, Natasha "Tasha" Yar (2337-2375) was a Terran female who served as an operative for Memory Omega during the late 24th century. She was trained by an elderly Vulcan woman named T'Lara.
In 2372, she was sent to the Klingon-Cardassian Alliance mining colony Korvat to deliver a message to Keiko Ishikawa, another Memory Omega agent who had become a slave overseer in 2365. Yar became a slave and was given the designation "701-Delta". Shortly after her arrival on Korvat, she made contact with Keiko and pretended to grant sexual favours in case they were being monitored while she delivered her message. The message, contained in a tattoo on one of Yar's legs, was written in Japanese calligraphy: "Our efforts proceed apace. Rebellion growing in Bajor sector. Proceed with training and liberation. Destination: Terok Nor."
Yar and Keiko began training dozens of slaves, including Tiron and Sam Bowers, in combat tactics in preparation. In 2375, after three years of meticulous planning, the two Memory Omega operatives staged a slave revolt in the Korvat mines. Approximately 200 slaves managed to reach the transport bay where Keiko and Yar each piloted one transport, each containing about half of their complement. Although the transports were both able to reach orbit and set course for the Badlands, they came under attack from a Klingon battle cruiser. As the starboard impulse engine of Yar's transport went offline and began leaking plasma, she provided a distraction which allowed Keiko's transport to escape to Terok Nor before her ship was destroyed by the Klingons. (DS9 - Mirror Universe short story: "A Terrible Beauty")