Many episodes in the Star Trek series present Captain Kirk’s darker side. “Mirror, Mirror” takes the concept a step further by presenting an alternate version of the entire universe. In fact, this parallel universe was explored several times on Star Trek: Deep Space Nine and in the Enterprise episode “In a Mirror, Darkly”. It has also been depicted in both the novels and comic books as well.
Instead of the benevolent Federation we’re used to, this universe is ruled by the Terran Empire. The Enterprise is given a new designation, ISS, standing for Imperial Starship. Every crewmember is antagonistic towards each other. Order is maintained with an “agonizer beam” rather than diplomacy. In fact, crewmembers will even kill each other to move up in rank. Kirk himself actually killed Captain Pike, his predecessor in both universes, rather than simply replacing him as he did in the original canon.
Kirk’s doppelganger is one of William Shatner’s best performances. Both versions of Kirk are ruthless, but “our” version of Kirk limits himself, giving himself lines he will not cross in order to maintain diplomacy. But his doppelganger has no such qualms. He has no inhibitions and his arrogance is not in check.
Spock’s counterpart, who even sports an evil beard, is another interesting parallel. He is still a logical person, but that logic is cold and calculating, with no human compassion. He is also the only one who seems to be loyal to Kirk, but there are hints that even his loyalty is false. He is merely biding his time until he can exploit his commanding officer’s weakness.
Perhaps the biggest surprise is Sulu’s evil counterpart. He despises those above him and does not wish to stay where he is. He wants to be at the top of the food chain, but is fearful of Kirk and Spock. When he sees an opportunity, he acts on those ambitions and soon pays for his arrogance.
This is an episode that has appeared on many “Best episodes” lists I’ve seen online and in articles, and with good reason. It’s a dystopic vision that doesn’t seem so farfetched. It shows just how ambition and imperialism can bring out the worst of humanity.