Episode Trivia


For all their high-tech advances, McCoy uses a plastic yellow bucket to hold the thermo-concrete he uses on the Horta.
While Kirk is waiting for Spock to arrive, after his meeting the Horta and sitting down, we see him holding his phaser pointed at the ground, near his waist. We then cut to a wide shot when Spock comes in and we see Kirk holding his arm stretched out, only this time he is holding his communicator. Then we cut back to a close-up of Kirk and his arm's holding the phaser again, pointing down.
Several times in this episode, Kirk uses his communicator and it doesn't "chirp" when he opens it.
Lt. Commander Giotto wears full commander stripes.
Spock informs Kirk that the Horta excretes a highly corrosive substance that lingers on the tunnel walls, yet in later scenes a portion of the creature and eventually the creature itself is touched with no ill effects.
Vandenberg opens the door to his office with a button on the underside of his desk - at different times he presses different spots on the desk.
Why did the Horta steal the reactor pump rather then destroy it? It's trying to kill the miners or get them off the planet - what advantage is there for the Horta to save it?
How did the Horta know exactly what part to steal? It's smart, but it doesn't seem to be familiar with human technology.
When Spock and Kirk pursue the Horta, they come to a fork in the tunnel. Kirk points right and tells Spock to go left. Then he points left and says he'll go right.
Sulu would later reference the events of this episode in "That Which Survives", even though Sulu does not appear in this episode.
During the confrontation with the Horta with Spock and Kirk, in one shot, Kirk's phaser is up, and the next shot, the phaser is down to his side.