In the mirror universe, the ISS Endeavour was a warship in the the Imperial Starfleet of the Terran Empire during the 23rd century. In 2277, the Endeavour was assigned to the Taurus Reach and was under the command of Captain Zhao Sheng. Sheng was entirely opposed to his sector commander, Commodore Diego Reyes, but Reyes had kidnapped someone he loved, so he was forced to follow Reyes' orders.