In the mirror universe, Thomas Blair was a Terran officer in the Imperial Starfleet of the Terran Empire during the mid 23rd century. He served aboard the ISS Indomitable. Following the execution of its captain Nathan Thorpe by Doctor Sarah April, the Indomitable's first officer Erin Stone became the captain while Blair succeeded her as the ship's first officer. However, their tenures in these new position proved to be short-lived as the Indomitable was destroyed by a Klingon battle cruiser in orbit of H'Atoria only days later. (TOS - Mirror Universe short story: "Ill Winds")