The original Star Trek featured a robust and diverse cast of villains, but with the exception of Harry Mudd and Khan Noonien Singh, audiences didn’t see them more than once. The nature of television at the time meant individual episodes usually had to be stand-alone stories, which meant a number of terrific villains from the original series never quite got their due. Season 1, Episode 14, “The Conscience of the King” featured one such nemesis: the genocidal serial killer Kodos, who actually managed to save James T. Kirk not once, but twice despite only appearing in a single episode.

Early Star Trek rarely gave these figures such moral ambiguity. They were memorable more for their menace than their nuance. But “The Conscience of the King” needed to flesh this villain out in order to make its central themes stick. As a result, Kodos carries the kind of depth that could have supported future appearances quite easily.

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In Star Trek canon, Kodos was actually a sort of precursor to the Marvel Cinematic Universe’s Thanos. The governor of an Earth colony whose food supplies were decimated by a fungus, he ordered the death of half of the population so that the other half might survive. Kirk survived the massacre as a teenager, and was one of the few people able to identify Kodos by sight, leading him to suspect the leader of a theatrical company to be the murderer in hiding. As captain of the Enterprise, he arranges for the troupe to be stranded, and then offers them passage to their next performance on the Enterprise, hoping to confirm his suspicions.

As it turns out, Kodos is a red herring. Having reinvented himself as an actor, he hopes merely to avoid detection. His daughter Lenore is the killer this time, using the troupe’s tour to cover up the murder of everyone who can identify her father. When Kodos learns the truth, he throws himself in front of a phaser blast to save Kirk.

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Beyond its entertainment value as a murder mystery, “The Conscience of the King” is intended to be a morality play, as Kirk debates with himself whether he’s seeking justice or revenge. Kodos’ acts of mercy muddy those waters considerably without excusing or justifying his crimes. Indeed, besides sacrificing himself by taking the phaser blast, Kodos saves Kirk’s life a second time after not killing him in his initial mass murder.

According to the episode, the former governor had dark ideas about eugenics and spared those he felt were “worthy” to live. One of them – Kirk – went on to rightfully condemn and judge him for it, and Kodos himself sacrificed his life to save that person: a chilling testament to how far he was willing to go for the “greater good” of his massacre. It lends ironic shading to the blood on his hands, which, coupled with his eleventh-hour confession at the end of the episode, gives an intensely evil figure the kind of nuance that turns stock villains into memorable ones.

It didn’t last more than one hour, which speaks more to the differences between television then and now than to the drama at hand. With only one appearance for their bad guy, the producers had to fit as much as they could – including a little-known but very important part of Kirk’s backstory that never gets mentioned again. That they took the time to develop a more textured villain – capable of saving his foe’s life twice – is a testament to the show’s quality, and to the fact that they refused to settle for run-of-the-mill.

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