In a Mirror, Darkly, Part II

In this episode, Majel Barrett reprises her role of a ship's computer voice (in this case, voicing the Defiant's computer). Her inclusion here meant she had been credited as a performer in all six televised Star Trek series, and all five live-action versions. As well as playing several characters (such as Number One, Nurse Chapel, and Lwaxana Troi), she also provided the voice for the computers aboard USS Enterprise, USS Enterprise-D, USS Defiant (NX-74205), various runabouts, and the USS Voyager. This episode was the penultimate official Star Trek production that she worked on, later voicing the ship's computer aboard the USS Enterprise of the alternate reality, in Star Trek (2009).

In his speech to the assembled crew, Archer says that the Terran Empire has existed "for centuries". This is impossible. He is speaking in 2155, and Terrans first learned that there were other planets out there to conquer in 2063. This gives them fewer than 92 years in which to build a trans-planetary empire. In fact the empire existed long before the discovery of other species. The Terran Empire flag is seen being planted on the moon. There's no evidence in the Star Trek universe to suggest that the Terran Empire was formed because they realised there were aliens. Instead this episode (including the speech in question) indicates that the empire existed long before they knew there were aliens. Terrans were already collectively violent and xenophobic when the Vulcans arrived.

The opening sequence is replaced with footage of various battles and a different theme song to reflect the fact that this is an alternate universe in which the Terrans are a warlike species.

Featured in The Captains (2011)