Star Trek: The Original Series

"The Enemy Within"


Air date: 10/6/1966
Written by Richard Matheson
Directed by Leo Penn

Review by Jamahl Epsicokhan

Unbeknownst to the Enterprise crew, a transporter malfunction creates a duplicate of Captain Kirk, which somehow receives all of the real Kirk's darker, "negative" qualities. The story documents Kirk and Spock's attempts to track the faux Kirk through the ship as the impostor runs around causing trouble—particularly in one episode where he has a rather nasty encounter with Yeoman Rand.

"The Enemy Within" epitomizes why TOS could be so much fun. We have mood and attitude injected into the anti-Kirk scenes, thanks to a wonderfully bombastic score by Sol Kaplan. We have William Shatner chewing scenery like there's no tomorrow ("I said give me the brandy!" "I'M CAPTAIN KIRK!" "I want to live!") in delightfully entertaining scenes.

And we have an effective balance of good dialog utilizing Kirk, Spock, and McCoy. Keeping the story grounded in the intelligent is the idea of the real Kirk's slow demise of will and his eventual inability to function as captain because he has been drained of the aggression that his counterpart possesses. It's an effective revisit to Jekyll and Hyde lore, and even though it can be campy at times, it's quite engaging along the way.

Previous episode: The Naked Time
Next episode: Mudd's Women

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23 comments on this review

Fri, Jun 1, 2012, 8:09am (UTC -5)
This is one thing I loved about this show--the men were all masculine. It did seem to struggle with the whole idea of women, but the men were strong, tough, and had that edge of masculine control and aggression--even Spock, who could take command, throw a punch, or take a risk with the best of them. Give me manly men any day!
Sat, May 25, 2013, 8:23am (UTC -5)
So you want to be fisted by manly men? If you say so, sailor. ;)
Nathan G
Sun, Aug 11, 2013, 10:30am (UTC -5)
Sun, Aug 11, 2013, 9:58pm (UTC -5)
Blah blah... Some problem in the atmosphere... Not enough, I dunno, ohms or something.
Mon, Sep 16, 2013, 4:06am (UTC -5)
As a Kirk-fan, this is one of my favorite episodes from the first season. Also, this episode highlights why I have come to love Star Trek - it's at its best when it raises interesting philosophical questions.
Wed, Apr 2, 2014, 8:29am (UTC -5)
One of the best. Like how the "good half" could not function without the "bad half" sometimes we need that.
Mon, Sep 8, 2014, 8:37pm (UTC -5)
I don't like the premise of the episode -- that a transporter malfunction could make a duplicate, one good and one evil.

HOWEVER, once I get past that, it's one of TOS' better efforts for reasons already discussed, especially for something early on in the show's run. (Maybe too early if you ask me).

Overall, a quite a good episode.
Tue, Oct 7, 2014, 10:37pm (UTC -5)
Yeah, the premise is a bit goofy (and the notion that Sulu and the other guys on the surface could survive at such LOW temps, AS IF, even with the best blankets and phasering all those rocks), but this is one of the better TOS episodes, for fun, and for philosophical value.

I laughed SO HARD when "Evil Kirk" was introduced in shadow, with an evil grimace. X-D All the scenes with Evil Kirk are so much fun to watch. This is what Shatnerian acting is made for.

But all the scenes with "Good Kirk" were well done as well. The notion that we "good" people all need our "evil" sides is a little hokey. (What they should really be saying is that we need our animal instincts, our ID, and we also need our prefrontal cortex, our reasoning, cooperation, compassion, our EGO and SUPEREGO - and that neither the ancient parts of our brain nor the more recently evolved parts are good or evil, they just are).

Oh well, it all makes for good drama. Except for the stuffed dog, I just LOL'd at how dumb it looks.
Tue, Oct 7, 2014, 10:38pm (UTC -5)
I should add that I really wanted to slap Spock for being so insensitive to Yeoman Rand. I mean, she was nearly raped by Evil Kirk! But oh the '60s - who needs counselling for attempted rape, right?
Wed, Oct 29, 2014, 2:07am (UTC -5)
Huh, I was underwhelmed by this episode. (My kids and I are going through and watching, in order, all the episodes Jammer has given three or more stars to; many of them I saw years ago in syndication but I don't recall seeing this one.)

Some of it may be just that certain elements are off because they are still working out the kinks: no acknowledgment that there are shuttles; strange, convoluted terminology to talk about the simple act of setting phasers to stun; the fact that Nimoy seems to be taking longer to settle into his character's groove than the other two of the main trio.

But that sort of points to part of the problem: we are only in the fifth episode, yet this is our second consecutive episode involving people being made to act differently from normal and run amok. And in fact, it is the fourth of the first five episodes in which at least one of the main actors deviates from the typical way they would play their character: either because someone or something was causing them to act nutty, or because they were playing an imposter. Shouldn't they have spent longer establishing their characters' normal behavior patterns first?

It was cool to hear that first "he's dead, Jim" though.
Jeff Bedard
Thu, May 14, 2015, 5:24pm (UTC -5)
@Nathan G: the behind the scenes reason for no shuttlecraft is that this early in the series the idea of the Enterprise having shuttlecrafts hadn't been created yet. So for the original audience of this episode it wouldn't have been a concern. But all these years later anyone viewing this episode will have a difficult time letting this in-universe gaffe slide.

I enjoy this episode, especially Spock's explanation of what is happening to Kirk and comparing his own inner battle with his Vulcan and human sides. I do wish the "evil" Kirk could have been more talkative. I understand that he is meant to personify Kirk's anger and rage, but EK still has intelligence and reasoning as well.

A few filming gaffes (some of the EK scenes are clearly reversed from how it was actually filmed) tend to annoy me a bit, but I like how even for 1966 and just a few episodes in TOS was tackling some wonderful philosophical and ethical issues. And William Shatner (for all the acting bashing he gets) does a superb job (in my opinion) of embodying two diametrically opposed versions of himself.
Wed, Mar 2, 2016, 3:41pm (UTC -5)
- I think this is the first aired episode with Spock and McCoy arguing on either side of Kirk. Fun to watch the Trek cliches snap into place. Bonus points for McCoy saying, "He's dead, Jim" about the space dog.
- Shatner's overacting in this episode is delightful.
- A good Star Trek twist on the idea of split personalities. So good they did it with Xander on Buffy the Vampire Slayer.

- This always bugs me on Star Trek, but particularly in this episode it seems ridiculous that they can beam people up from a planet but can't track somebody on their own ship. No security cameras in the future, I guess.
- Spock's last line is way out of line and way out of character.
- The pacing drags a little, as per usual. Shows now are much more exacting in how much they reveal to the audience over the episode. I've noticed with this early going in Trek that the audience knows everything all the time, often long before the crew does.

While I like Shatner's hamminess, I could do without his screams.

Three stars of four.
Sun, May 29, 2016, 11:56am (UTC -5)
@Nathan G


The shuttlecrafts weren't available until Tuesday.
Wed, Jun 22, 2016, 9:35pm (UTC -5)
Well, it had to happen eventually. It was only a matter of time before William Shatner went full-ham. And what a hamfest it was. "I'm Captain Kirk!!!" indeed. I like to imagine that nowadays he does that whenever he sees Christopher Pine.

Anyway, I bring that up because, unfortunately, that was probably the worst part of the episode. Yeah, a split personality like that isn't exactly the most original idea in the world, but it had potential. Unfortunately, the dramatic BAD GUY! music every time evil-Kirk shows up, along with the over the top acting, kinda ruined it for me. I would have appreciated a bit more subtlety in his actions and in his interactions with good-Kirk.

For example, the scene in sickbay when evil-Kirk tricks good Kirk into freeing him. Good scene! Evil Kirk was cunning, manipulative, and took advantage of goodKirk's indecisiveness and inability to lead. Likewise, the scene in Engineering where good Kirk discovers he isn't afraid while evilKirk realizes he is paralyzed with fear. So there are some good scenes here. Why did they have to ruin it with the over-the-top portrayal as well?

Likewise, I was surprised that the goodKirk vs evilKirk plot was so thin and finished about half-way through the episode; I seemed to recall the battle in Engineering to be a lot closer to the end than it actually was. So I guess it was a bit weird that there wasn't much focus on action or intrigue, given that they set up the imposter as being a big deal. Instead, it was mostly some philosophizing about the nature of human duality and worrying about Sulu and company freezing to death.

At least those scenes were ok. I mean, I could have done with less Sulu (we know he's in peril, no need to pad it out). But fortunately, while evilKirk was hammy, goodKirk was pretty subdued. I like the lack of ability to command, as if all his testosterone went to evilKirk. He simply looked so drained talking to Sulu, barely able to keep up that task. If the point was to show that a person couldn't function without their base animalistic side, even if said side needed to be properly controlled, then I guess the episode worked. Good Kirk really did seem like half a man, and you could see why he desperately wanted to return to his previous self.

It's a bit of a shame that Spock's character wasn't fully established yet. Spock, of course, completely suppresses his emotions, believing them to be a detriment to functioning in society. Yet here, it is shown that Kirk's base emotions are required to function, even if they must be seriously controlled. It shows that Spock perhaps has the right idea to some extent, but helps to explain why Kirk is the captain and he is not. Of course, with Spock's character not fully fleshed out, this comparison to his own nature, which one think could be an obvious parallel, is ignored.
Wed, Jun 22, 2016, 10:19pm (UTC -5)

I've just started my TOS recap so I'm not here yet, but to your point about evil Kirk's presentation;

1) the show is a product of it's time, the 60's. The days of stereotypical mustashe twirling villains who tied women to train tracks wasn't relatively long ago. It was still an acceptible and legitimate way to portray the Evil characters. Probably in accordance with the Hays Code, which dictated these things.

2) While likely a concept many sci-fi fans had seen before, during the 60's an evil identical duplicate seperated from our main good character was probably completely new to the general TV audience of the 60's. They probably needed that level of handholding to keep the story straight for them.
Wed, Jun 22, 2016, 10:41pm (UTC -5)
Pfft, recap, I meant rewatch. I was also going to mention not quite remembering the episode, instead of implying it, so take my counterpoints with a grain of salt though I think they do stand up.
Peter G.
Thu, Jun 23, 2016, 12:49pm (UTC -5)
@ Skeptical,

I would suggest to you that 'evil Kirk' was portrayed over-the-top because he wasn't mean to be evil, but rather animalistic and wild. Imagine a directive from the producer that you're supposed to basically be a crazed wildcat or some other vicious animal with no ability for self-reflection. How would you portray that? Animal-Kirk can't even be described on the sanity/insanity scale since he literally lacks higher reason and the ability to contemplate. Have you heard the expression "to go apes**t"? That applies here, especially if you're seen videos of territorial and angry apes.

I've seen people IRL or caught on video who were crazed beyond all reason, sometimes about trivial stuff. They still had the capacity to reason but didn't or couldn't; animal-Kirk can't. What seems like 'over-the-top' on TV is probably a product of whitewashed gentile behavior as normally shown on TV, where even 'evil' people are controlled and rational in some sense. But in real life people do go haywire and it can look over-the-top too. Sometimes I observe people IRL and say "wow, that behavior looks so fake" even though it's 100% real. It just means our sense of 'realistic' as defined by TV and film is bogus.

I buy Kirk's behavior in this episode, and although I think it's only middling Star Trek my main problem with it isn't how Shatner portrayed the wildness.
Thu, Jun 23, 2016, 8:35pm (UTC -5)
Nolan and Peter (and spoilers below as a word of warning for Nolan),

The one problem with a counterargument that hammy evil-Kirk is ok is that evil Kirk was not always hammy. The scene in sickbay has evil-Kirk slowly succumbing to good-Kirk's arguments, seemingly agreeing with him while showing fear about the future. But as soon as good-Kirk lets him free he betrays him. He then calmly went through several steps to try to trick the crew into thinking he was good Kirk, like changing his shirt, putting makeup over his scratches, etc. His second attempt to get into Rand's pants was a lot more civilized than the first (even if it was only because they were still in the hallway).

What this means, to me, is that he's not just a base, animalistic, primal side. He does show the ability to plan, to think ahead, and to bide his time. Those are signs of intelligence. It's basically a more subtle villain than the I'M CAPTAIN KIRK we saw 20 minutes ago. So I don't think you can just blame this on 60s-era TV making villains wear black hats (besides, Balance of Terror and IIRC Errand of Mercy will show more subtle villains this season). And I don't think you can claim evil-Kirk has no reasoning capacities given his subterfuge.

I guess if the entire episode was hammy evil-Kirk, I would just sit back and enjoy it for what it is. But the fact that there were signs of him not being so crazy just ended up frustrating me...
Peter G.
Thu, Jun 23, 2016, 9:50pm (UTC -5)
I didn't say animal-Kirk had no ability to reason, Is specifically said he lacked self-reflection. He could reason on a tactical level as well as any animal. Have you seen some of the strategies animals in the wild use to hunt? It's better than what most people could come up with if they sat down and planned it out. It's done by instinct, but on the fly they improvise and implement tactics using the powers of their reason. They are not therefore without intelligence, but merely without the ability to conduct abstract self-examination or to question their choices. Animal-Kirk may have employed various strategies to get what he wanted, but in the end his entire motivation was based on the fear of a trapped animal. In that sense I think we're supposed to eventually see him as pitiable, which is why I refrain from calling him evil-Kirk. He has no moral status because he's not capable of moral judgements. He has just enough wherewithal to see reason in the end - barely.
Mon, Dec 26, 2016, 8:24pm (UTC -5)
Did no one catch the horribly dated social norm, when Yeoman Blonde is nearly raped and swears that she wasn't going to tell on the captain, because she didn't want to get him in trouble? Are we supposed to give her a thumbs-up for her loyalty?
Mon, Jan 16, 2017, 3:38pm (UTC -5)
The most cerebral of the 1st 5 Star Trek TOS episodes - a take on Jekyll/Hyde and an interesting choice to air so early in the series. Shatner does a good job portraying the 2 Kirks. Spock's character is still evolving -- he seemed to show a bit of excitement theorizing what has happened to Kirk to McCoy; also not a fan of his final line to Rand - very out of character. I guess they didn't take attempted rape very seriously in the 60s.
Through 5 episodes, Rand plays nearly the most significant role after the big 3.
Have to assume the Enterprise didn't have shuttlecraft yet.
The most important thing is that it puts forth a concept of what characteristics might go with good vs. evil, a good subject for Trek to weigh in on.
For me, I'd rate it 2.5/4.
Sun, Mar 19, 2017, 10:21pm (UTC -5)
Great episode, but as Lal mentioned, that last line by Spock was completely out of line. Whoever added that should be taken out and shot.
Mon, Mar 27, 2017, 7:09pm (UTC -5)
Brilliant, a very important acknowledgement of the uncomfortable part of ourselves being actually very useful, and I think present day people could learn a lot from this.

I apologise if this is insulting or something but I think the two Kirks can be argued as similar to "the left" and "the right" - the carer/nurturer and the red blooded go getter, and rather than being at each other's throats we need each other. We're living in a time when we're pretty much Kirk vs Kirk right now.
Similar with Spock and the battles he shows between his Human and Vulcan sides.

I feel sorry for Yeoman Rand - constantly the subject of sexual harassment in I think every episode she's appeared in so far!

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