Star Trek: Season 1, Episode Five “The Enemy Within”

Original Air Date: October 6, 1966
Stardate: 1672.1 (2266)
Writer: Richard Matheson
Director: Leo Penn

Can half a man live?

Rating: 5 out of 5.

The USS Enterprise is conducting a specimen gathering survey on Alfa 177, a craggy planet which contains a rare native dog species. During the expedition, a Geologic Technician named Fisher takes a fall and accidentally scrapes his arm on a strange yellow metallic ore. When he is beamed back aboard the Enterprise the magnetic ore causes an overload malfunction in the transporter (Scotty calls it a “burnout”). Before the engineers can discover the problem Captain Kirk is also beamed back aboard the ship. Unbeknownst to anyone, he has now been entirely split in two –between his good and evil halves a la The Strange Case of Dr. Jekyll and Mr. Hyde.

Technology has once again failed the crew and they must discover the unruly alter ego of Capt. Kirk before something terrible happens. The alternative Kirk steals a bottle of Saurian Brandy and corners Yeoman Rand in her room (she scratches his face and narrowly escapes from his clutches in a shocking scene of assault which was cut for syndication). Eventually Kirk #2 attempts to commandeer the ship. Meanwhile, down on Alfa 177 things begin to grow dire as Sulu and several others huddle for warmth on the freezing planet just as night begins to fall (earlier in the episode Kirk noted that it gets down to 120 degrees below zero on Alpha 177). For now they are trapped in the cold because there is not a functioning transporter on the Enterprise.

And what is it that makes one man an exceptional leader? We see here indications that it’s his negative side which makes him strong, that his evil side, if you will, properly controlled and disciplined, is vital to his strength.

In most Star Trek episodes we are confronted with the dilemma of how to make a good or noble decision amidst the vast and a-moral emptiness of the cosmos. How shall we deal with a child who is given strange powers? What to do with a crew member who believes himself a god? However “The Enemy Within” shows us an internal conflict within Capt. Kirk. He contains both good and evil within himself. Like Spock who is often split between his Vulcan and humans halves, Kirk is also divided between animal and man, or Apollonian and Dionysian counterparts. Yet despite his nobler ambitions, Kirk still requires the presence of his evil side –it gives him the confidence to govern and the cold distance necessary for strong leadership. Interestingly enough, in Star Trek evil is reaffirmed as a strange necessity for human life though it must be balanced with an abundance of good for a kind of Aristotelian moderation. Eventually, the Enterprise crew captures and contains the evil Kirk (Spock uses the Vulcan Nerve Pinch), and in the end both Kirks are sent back through the transporter again –this time the transporter has been fixed (though this will be not be the last such malfunction in Star Trek). Now the reformed and newly confident Capt. Kirk orders a rescue mission of Sulu and the other frostbitten crewmen from the planet’s surface below.

I’ve seen a part of myself no man should ever see.

My Thoughts on “The Enemy Within”

While technology is often viewed as a neutral tool which operates in the service of mankind, “The Enemy Within” examines the ways in which technology can reveal strange and disturbing aspects of the human condition. Bearing elements of the evil doppelgänger mythos –a trope which is also put to good use in The Twilight Zone— the struggle described here is one of an internal conflict. What if we had to chance to truly confront ourselves and this immense complexity of existence? What if the inner struggle suddenly became public and the worst demons of our nature were put on full display? Captain Kirk is forced to reckon with himself in “The Enemy Within” and he soberly acknowledges a certain degree of evil within himself.


Legendary writer Richard Matheson (1926-2013) was the famous author of I Am Legend (which was later made into several film adaptations). Of course, he was also a writer of many classic episodes of The Twilight Zone, including “Nightmare At 20,000 Feet” which also featured William Shatner. Matheson is an example of the kind of talent Star Trek was able to attract in its early production, unfortunately this was the only Star Trek script Matheson ever penned.

Director Leo Penn (1921-1998) was never invited back to direct another Star Trek episode because he ran a day over filming on this episode and thus the episode ran over budget. Interestingly enough, Leo Penn was the father of Sean Penn.

Star Trek Trivia:

  • The subplot of Sulu and several crew members stranded on a frigid planet was not in Richard Matheson’s original script and he did not approve of the idea.
  • The original script had Spock karate-chopping Kirk but Nimoy thought this was far too violent for a peace-loving species like the Vulcans, so he developed the Vulcan Nerve Pinch instead.
  • The Enterprise’s shuttlecraft was not yet introduced in the series however it would have made an easier rescue of the stranded crewman.
  • This is one of the few Star Trek episodes where you can see James Doohan’s (Scotty’s) missing middle finger on his right hand. He lost the finger on D-Day in 1944 when it was struck by either a bullet or shrapnel. He made great efforts to conceal his missing finger during the filming of Star Trek.
  • This episode features the first time Dr. “Bones” McCoy utters his famous phrase “He’s dead, Jim” –a reference to the dog who dies in an experimental fix to the transporter.
  • This episode was the first in a long list of episodes dealing with transporter malfunctions.
  • Yeoman Janice Rand’s quarters are located at 3C-46. However, in “Charlie X” Rand’s quarters are 3F 125.
  • The scene of the evil Kirk attempting to force himself upon Grace Lee Whitney, who plays Yeoman Rand, is made all the more disturbing in hindsight when considering that only in a few episodes time Grace Lee Whitney would be sexually assaulted by an unnamed executive at NBC and then fired from the show leading to years of substance abuse. She was brought back for the Star Trek movies in the 1970s after Deforest Kelly spotted her in an unemployment line. In her autobiography she took umbrage with Spock’s closing line in this episode: “…the impostor had some very interesting qualities, wouldn’t you say, yeoman?”
  • Gene Roddenberry listed this episode as one of his ten favorite episodes.

Click here to return to my survey of the Star Trek series.

1 thought on “Star Trek: Season 1, Episode Five “The Enemy Within”

  1. One most commonly dramatic issue in our sci-fi, certainly when it comes to futuristic mishaps with our advancing technology, is how much self-mastery we actually have. The Fly made a point that a teleportation technology would naturally come with great risks in this regard. For Star Trek and of course one of Shatner’s most shining moments as Kirk, it one of the show’s first dramas to help fans understand why such conflicts continue to be educationally necessary, even in an optimistic future.

    Liked by 2 people

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