Whether they’re created by time travel or simply by the possibilities presented by the roll of a dice, some of the best moments in science fiction have happened while hopping between parallel worlds. Sometimes alternate dimensions are a place of unspeakable evil, other times they’re a perfect example of what might have happened had we gotten it right the first time. These are the ten best alternate dimensions in science fiction.
The Mirror Universe as seen in the Star Trek episode “Mirror, Mirror”
Star Trek’s “Mirror, Mirror” universe episode made such an indelible mark on our culture when it debuted in 1967 that it’s still the default way of explaining alternate dimensions, in just about any context. Like all the best original Trek episodes, it still holds up.
It revolves around a transporter accident which sends Captain Kirk, Dr. McCoy, Scotty, and Uhura to a nearly identical, yet fundamentally different universe. There the Enterprise is the tool of an organization called The Empire, which uses it to murder and threaten anyone who opposes it. They must attempt to blend in with a crew full of bloodthirsty killers, including an evil, goatee wearing Spock, while looking for a way to get back to their own universe without actually having to commit genocide. Other Star Trek series went on to visit the Mirror Universe, but none of them ever did it as well as they did it the first time. Remember to put on a goatee the next time you want to do something evil, then blame it all on your Mirror Universe counterpart if you get caught.