In the mirror universe, Tactical Cube Beta was a 25th century Borg starship, a tactical cube in Borg Kingdom service in the 2410s decade. Alongside Tactical Cube Alpha, Beta operated from a unicomplex. (STO - Incursion mission: "Guillotine")
Service history and disposition[]
The Borg Kingdom began utilizing a type of interdimensional portal known to the Khitomer Alliance and Tholian Assembly as a reality vortex. Reality vortices could be used by the Borg to create beachheads in their multiversal conflict with the Aetherian Concordium. (STO - Kings & Queens mission: "Taken By Surprise")
In the year 2411, the mirror unicomplex emerged from a reality vortex in various locations. Leader Thaseen-Fei of the Aetherian starship Harmony coordinated the Alliance assault on the facility and its technology. After the Harmony had set up the stitching network to close the vortex, the unimatrix launched the pair of tactical cubes to attack the Aetherians. The Alliance forces destroyed the tactical cubes and their Borg sphere and assimilator reinforcements. With the stitching network established, the reality vortex collapsed and expelled the unimatrix.