9 Most Memorable Alternate Universe TV Episodes 

Three Star Trek television series have crossed over into a specific alternate reality known as ‘The Mirror Universe’. In that world, human morality is twisted and evil. It is a timeline where humanity never evolved socially beyond a destroy and conquer mentality. Star Trek: Enterprise perhaps committed most fully to the concept with a two-part episode, In A Mirror, Darkly. The show went so far as to brilliantly, without fanfare, change the opening credits to show an alternate and brutal history of Earth evolving toward the eventual launch of the Warship called Enterprise, instead of the usual opening’s inspirational imagery.

Commander Archer is the first officer of the ISS Enterprise, jewel of the Terran Empire’s fleet. After Captain Forrest refuses to investigate a potentially beneficial piece of technology, Archer pulls off a successful coup aboard the ship and ascends to the rank of Captain. The aforementioned technology was revealed to be a ship from the future of the prime universe. Its superior firepower and technology from the future would make whoever controlled her into the new Terran Emperor.

These two episodes, which aired during the show’s fourth season, gave the viewer a fun look through a grotesque, but familiar, funhouse mirror. By setting the episodes apart from the series, and not crossing any characters between the two timelines, the show checked in on the beloved alternate universe without adding to an already hurriedly jam-packed final season in the prime universe. By playing with both timelines and time itself, the crew was also able to pay respect to The Original Series by showing us the Enterprise crew in the yellow (but sometimes green), blue and red uniforms that made the franchise famous.