Star Trek: Dark Mirror

Star Trek: Dark Mirror is a non-canon novel (not connected to the Star Trek Novel Verse) written by Diane Duane, set during Star Trek: The Next Generation, and it revisits the Mirror Universe from the original series.

During a visit with a nomadic space fleet to pick up a Starfleet researcher, the USS Enterprise-D finds itself in the same Mirror Universe that Kirk visited in the episode "Mirror, Mirror". Worse, they find out that the mirror version Enterprise-D is working on the means to invade the Prime Universe.

It's not considered part of the novel verse canon as it contradicts the official depictions of the Mirror Universe from Star Trek: Deep Space Nine, and is considered a "what-if" story in a different timeline.


 * Agony Booth: Makes a proud return. They even have an improved miniature version for on the spot Cold-Blooded Torture.
 * Alternate History: History diverged sometime during the writing of the Iliad, and morality inverted from that point onwards. The contemporary Star Trek canon even begins with an altered version of the Eugenics Wars in which Khan Noonien Singh was the victor.
 * Bigger Is Better: A practical version of this trope is used on Mirror Universe vessels, since bigger ships means more space for more powerful engines and weapons.
 * Broad Strokes: The story of this novel is hard to reconcile with any Mirror Universe depiction set from the DS9-era onward, where the backstory differs considerably, and at best can merely be considered an alternate universe take on the original Mirror Universe, in which the Terran Empire never fell.
 * Dark Reprise: Prime Universe Picard is horrified to find out a literature variant of this has occurred to the works of William Shakespeare and Plato. All the works of Shakespeare where any character exhibited a hint of decency have been rewritten or those parts are omitted. Plato's work now argues for a dictatorship instead of a republic, by the alterations of some lines in the original.
 * Doppleganger Squad: The Terran Empire is intending to weaponize this as a tactic against the Prime Universe..
 * Deadly Doctor: Mirror Crusher's specialty, which disgusts her prime counterpart.
 * Downer Ending: Picard discovers Mirror Spock did try to take Prime Universe Kirk's urging to change the Mirror Universe to heart..
 * Expy: Mirror Troi's job description and activities could have been taken from an average female Psi Corp officer's daily life.
 * Extreme Doormat: Mirror Worf, since Klingons have been reduced to a Slave Race.
 * My Significance Sense Is Tingling: Commander Hwiii's version of this provides the Prime Universe crew their first warning they aren't in their own universe anymore.
 * Nightmare Fuel: In-universe, the moral inversion of his favorite works of literature is this to Picard. So much so, that after being horrified by the changes in Shakespeare and Plato, he doesn't dare check to see what The Bible has become.
 * Starfish Aliens: Commander Hwiii comes from an alien species of sentient dolphins.