Pifias

When McCoy and Spock leave the bridge after Spock's near-collapse in the opening scene, Kyle, at the helm, is wearing a red shirt. McCoy gives Spock an examination, but does not confine him to Sickbay, so one can assume that Spock is only off the bridge for a couple of hours at the most. When he returns, Kyle is wearing a gold shirt.

Spock and McCoy are standing outside the shuttle craft hangar bay doors. Bones is wearing a short-sleeved medical shirt but, in the quick close-up of his fist punching the 'Open' button, it turns into a long sleeve shirt with a gold-banded cuff.

The black-haired Mr Sulu is replaced as helmsman in this episode by Mr Kyle, who has blond hair. But a stock shot of the view forward from Kirk's chair shows a helmsman with black hair.

Mr. Leslie, at the engineering station, starts the episode with the braidless sleeves of an ensign (these can be best seen about six minutes into the episode, with Leslie in the background of a closeup shot of Kyle and Chekov). When McCoy comes on the bridge with stimulants, however, Leslie's sleeves bear the single solid braid of a full lieutenant.

When the Enterprise enters the body of the organism, there is a violent impact which knocks Uhura and her chair to the ground. The camera cuts briefly to the Enterprise inside the organism, and when it returns to the crew just a moment later, Uhura is still sitting in her upright chair as if it never fell over.

As Spock is about the enter the shuttlecraft hangar, McCoy presses a button that opens the door. The button's nameplate states "hanger" when it should read "hangar".

When Chekov suggests the area of darkness could be an interstellar dust cloud, Spock says "not likely" and Kirk refutes the idea: "you would be able to see stars through a dust cloud." In fact, galaxies are full of star-obscuring dust. The center of the Milky Way is invisible from Earth because of all the intervening dust clouds.

In his supplemental log entry, Kirk states that they have stopped the engines. Had they done this, the ship would be drawn further into the "zone of darkness" as it was later, when they actually cut the engine thrust. Additionally, the engines go into reverse because of the amoeba's negative energy field. If they were stopped, this would not have happened.

When Dr. McCoy and Nurse Chapel are looking at the monitor over the crew member who is dying, the far left temperature reading is almost at the bottom. Temperature would decrease slowly from normal, after a death - not immediately.

After Kirk orders magnification 3, the "hole in space" does not appear any closer or larger. This perceived goof did not exist until the remastered edition. The actual remastering goof was the hole being visible at all when Kirk says "scanners on." In the original version, the hole was not visible at all until Kyle magnified the image and Spock, replying to Uhura's question, says, "I would assume...that!"

As they were approaching the dark cloud, Uhura said that she couldn't receive communication from Star Fleet due to interference which was getting worse. However, moments later, Kirk asks Uhura to notify Star Fleet and Uhura reports that the transmission was complete, though interference prevented contact earlier. However, there is a difference between being able to receive a message and sending one out. They were simply sending a transmission out and hoping for the best.

The shuttle craft used is the "Galileo" which was destroyed in The Galileo Seven (1967). However, that incident was over a year earlier. In the time since, the "Enterprise" would have put in for re-supply at least once and possibly twice. The "Galileo" was simply replaced.

When the Enterprise is approaching the zone of darkness, Chekov says they will enter it in one minute, seven seconds. They penetrate in thirty-seven seconds. However, this is merely an editing issue: events in TV or movie dramas rarely play out completely in real time.

When Lieutenant Kyle gives the distance to the organism as 100,000 kilometers, the Enterprise is traveling at the speed of light (warp 1). At such a velocity, the ship would be inside the organism -- and then beyond it -- less than a second later.

At one point during Kirk, Spock, and McCoy's discussion of using a shuttle craft to determine how to destroy the organism, McCoy crosses over so that he is next to Spock, but the cuts between them show exactly the same background, even though they are facing each other. (This was because there was no wall on the set behind McCoy, from Spock's point of view).

(Remastered version only) When Kirk orders scanners on, but has not yet requested "magnification 3," the zone of darkness should not yet have been visible on the screen, but is.

When the "Enterprise" is being sucked into the amoeba, the engines are stopped but the engine sound effect is still heard.

After McCoy says "we're all dying", the camera moves closer to Kirk and its shadow is seen on Kirk's chair.

Given all the medical problems on the ship, McCoy should have returned to sick bay to help his medical staff, after had treated the bridge crew, instead of staying on the bridge to watch what's happening.

Kyle counts in kilometers while Spock counts in miles.

One of the times the organism is making the painful noise, Kirk briefly covers his ears, then takes his hands away and acts as if the noise isn't bothering him. Everyone else is still in pain, covering their ears.

Kirk refers to John Winston's character as "Mr. Cowell" several times. His enunciation is clearly "Cow-ell". Winston is listed as playing "Kyle" in the credits. The closed captioning shows "Kyle" as well.

While the noise from the organism causes everyone to block their ears and writhe in pain, Kirk is premature in removing his hands from his ears and saying, "What 'was' that?" At that point, the noise is still happening.

When the initial probe emits a loud high-pitched tone, everyone on the bridge grasps their ears and falls about in pain, with the exception of Mr. Spock, who shows no reaction at all. Spock's hearing was many times more keen than that of his human colleagues, and the sound would have been unbearable for him. Therefore even with his Vulcan emotional control, a logical response of covering his ears so that he could keep monitoring his station ought to have been displayed.