Mirror Archer takes the 23rd-century Defiant from the Tholians and uses it in a bid for power, but he is betrayed.
The ISS Enterprise is destroyed by the Tholians, and Mirror Archer and his surviving allies take control of the USS Defiant. A Gorn named Slar sabotages the ship and is killed by Archer, while Mirror T'Pol leads a failed alien uprising aboard.
Archer uses the Defiant to defeat a rebel fleet, then heads for Earth intending to make himself emperor. Before he can do so, Sato, his companion, poisons him and declares herself empress of the Terran Empire. The episode was directed by Marvin V. Rush, with a teleplay by Mike Sussman.