There is much to commend this episode, not the least of which is that it introduced the world to Trek. But it does so with what must be viewed as a rather routine monster story which was not up to the quality they would attain in a very short time period (and had already attained to a certain degree, though it hadn't been seen).
While there are modestly interesting details in the script, the plot is standard fare. There is nothing uniquely Trek about it. Mind-reading and shape-shifting, two of the central ideas, were already long-established sci-fi concepts. The monster stalks its victims in a fairly routine fashion, and its reason (hunger) has none of the drama we would later come to expect from the show. When the monster theme returned a few weeks later (as "Devil in the Dark") the motivation would be much more mysterious and much more effective when finally revealed. The creative team learned a great deal in the first few weeks.
Late in the episode we hear about the buffalo, and one can imagine that this story was originally conceived as a morality tale about preserving endangered species (still a relatively new concept at the time). But no discussion ensues. Kirk and crew never even consider the ramifications of killing the last salt vampire, nor do they contemplate any course other than killing it. Later Trek would at least raise the question among our crew (having the monster itself, in the visage of McCoy, raise it does not really count because it's not one of our characters).
The problem is that the script lets the jeopardy get out of hand and keeps the crew in the dark too long. The mystery remains for almost 40 minutes, despite the fact that clues are dropped left and right. In the end, the sheer body count (five dead, not counting the original Nancy Crater) leaves Kirk with no alternative but to kill the thing. Had the jeopardy been played with a bit more subtlety, there would have been less urgency for Kirk to save his crew. In that case, he might have considered capturing the creature instead of killing it. A better structure would have been to reveal the existence of the monster at the end of the second act, consider ways to save it during the third act, then try to save it but fail during the fourth. Unnecessary killing simply occupies too much of the story.
So by the time they figure out what is going on, there's too much at stake. The thing is just too dangerous and must be destroyed, no discussion allowed. The dazed McCoy does have to kill something that looks like his lost love, but a small critical error is made. While attacking Kirk the first time, McCoy is allowed to see the monster as it truly is. Since he now knows then that it is a monster, he's off the hook with no choice to be made. It looks like Nancy, but he knows it's a monster. By holding off and not showing him the truth, a fine choice could have been set up: should McCoy trust his shipmates and kill something that looks like his lost love? This could have been easily fixed in editing, and later Trek would get this setup right more often than not.
Of course, the salt vampire probably cost a lot of money, and they wanted to show it off as much as possible. But how much more effective would it have been if they had held off until it was dead? Once dead, they could have done numerous shots from various angles and gotten their money's worth. It is a beauty, no question about that.
A benefit of all the killing is that we get long look at the activities aboard a starship. We get to see Sulu pursue a hobby, Rand deliver food trays, various crewmembers hang out in the corridors, Kirk and Spock go back and forth to the planet a couple of times, McCoy relaxing in his quarters, Kirk snacking, things like that. In that sense, the episode succeeds very well in introducing the setting for the series. Similarly, the monster movie approach would have been comfortable for new viewers, with enough action to satisfy the network. Looking at the first few episodes, it is clear that they made a wise choice on which one to air first.
The creature is well-played by a succession of actors. The unity of this performance is a tribute to director Daniels, who maintained signature elements across the portrayals, seemingly derived from Bal's initial turn as the creature. Though the individual roles are small, it feels like one character and one long performance. This is quite a difficult task, handled very well. Also handled well is the creature's keeper, and Ryder is very effective in the role, although the character is somewhat underutilized. One can imagine an alternate version in which, instead of trying to hide the nature of the creature, he makes eloquent arguments for saving it right from the start, then tries to prevent Kirk and crew from killing it when it becomes clear that is the only option.
The monster-movie qualities of the episode are unintentionally aided by Courage's moody but disappointing score. The use of electronic keyboards creates a tension, but it's the Bela Lugosi sort of tension you might find in a cheesy B-movie. Some elements of the score would find their way into the toolbox of music, and there they would be used very well, but here they basically disappoint. At this point in the production, all hands were hoping that Courage would be the primary composer. That would probably have been a mismatch in the long-term, and we would never have gotten to hear Fred Steiner's signature work which so defined the series throughout its run.
The ship sets were still new, and there was much experimentation with just how far they could be pushed. So we see the briefing room redressed as a lounge, the sickbay redressed as a botany lab, and the corridors relit several different ways to give the sense that they extend much farther than the set actually did. Likewise, the planet exterior is quite convincing as a dead world covered with ruins. Unfortunately, it is also covered with sand, and it's a bit undignified to see Kirk and Spock crawling about kicking the stuff up and running in zig-zag lines. There is a nice combination effect when the ruined column is destroyed. It seamlessly combines the optical of the phaser with the on set crumbling and smoke. They wouldn't get this fancy very often, but they were just getting their feet wet, and this worked beautifully. On the other hand, another special effect, the living plant, is too obviously a puppet. Thankfully, they never tried this again.
Nimoy is to be commended for finally sounding most of the right notes in his portrayal of Spock. The bemused smile is gone, as are the rosy cheeks, although facial expression (which he would later severely control to remarkable effect) is still a bit loose at times. But the essential tone of the character is now in place (despite the fact that he suddenly becomes a punching machine toward the end -- a problem of the script, not Nimoy).
The episode is, in many ways, the quintessential early Trek. What it lacks, however, is a compelling reason to tell the story. It comes close to finding something by leaving McCoy in the dark as everyone else finds out what's going on, and by mentioning the buffalo as a contemporary comparison. But close is not enough. Trek would do other monster movies, but they would mostly be motivated by something much more interesting from a human standpoint. Here, with the simple motivation of hunger, the ramifications of decisions are easily glossed over and quickly forgotten.
Rating: Middle (4)