As the years went by and the franchise changed, we saw the mirror world evolve as well as more characters came face-to-face with their mirror selves who, for the most part, were very different. On October 6, 1967, the Star Trek: The Original Series episode “Mirror, Mirror” showed us a parallel world with an Empire instead of a Starfleet and United Federation of Planets. Looking at all these, here’s how I would rank Star Trek’s mirror universe episodes from worst to best. However, while some of the episodes that followed “Mirror, Mirror” made for fun, interesting additions to the idea of the mirror universe, others lacked the same creativity and did not take full advantage of the world’s potential. It was a place the franchise would return to in five episodes of Deep Space Nine and a two-parter on Enterprise. Like Captain Kirk before them, our favorite characters often intervened in the mirror universe’s affairs, leading to changes we’d only discover in future episodes.