History NightmareFuel / StarTrekTheOriginalSeries

** Because the tribbles are featureless balls of fluff, the true horror of this scene doesn't always land with some people. But imagine unexpectedly finding yourself covered in the corpses of literally any other animal. Hundreds of them. And while most are recently deceased, Spock's dialogue implies that some of them could have dead for as many as three days; which would put them well into the initial stages of decomposition. Nobody would blame you for crawling fully-clothed into the nearest [[ShowerOfAngst shower]] with a large bottle of [[BrainBleach whisky]].

* The episode is mostly a lighthearted comedy, but the scene at the end where dead tribbles fall on Kirk until he's standing nearly waist-deep in them is very... disturbing. It's the equivalent of opening the door to the attic and being bombarded with dead kittens, and they just kept falling as Kirk was standing there, probably from being casually tossed aside by [[spoiler: Dax and Sisko]]. And it was played for comedy. ''Twice''![[note]]: It actually took ''many'' takes to get the scene right - William Shatner's weary exasperation [[EnforcedMethodActing wasn't acting]].[[/note]]

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that everyone on the planet gets to unleash their repressed emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''. One poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. The situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]'' [[note]]Indeed, the creator of ''The Purge'' took major inspiration from this episode.[[/note]] It's especially frightening to consider just how many women on the planet might have been impregnated against their will during "Festivals" and how many people on the planet were [[ChildByRape conceived due to rape]] over the thousands of years Landru ruled Beta III.

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that everyone on the planet gets to unleash their repressed emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''. One poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. The situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]'' [[note]]Indeed, the creator of ''The Purge'' took major inspiration from this episode.[[/note]] It's especially frightening to consider just how many women on the planet might have been impregnated against their will during the "Festival" and how many people on the planet were ChildByRape.

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that everyone on the planet gets to unleash their repressed emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''. One poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. The situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]'' [[note]]Indeed, the creator of ''The Purge'' took major inspiration from this episode.[[/note]]

[[caption-width-right:350:This...thing is from the ''first'' episode, by the way.]]

* The machine is pretty much a preview of the Borg--unthinking, unfeeling, and feeding its insatiable hunger by devouring whole planets for unknown ends. Add to that that it is made of metal so dense that the entire Federation fleet could unload its entire arsenal on the machine and it wouldn't be [[IncrediblyLamePun phased]], and is, by a wide margin, the most powerful weapon ever seen in the franchise (more-or-less on par with the [[Franchise/StarWars Death Star]]) and you have one pants-shittingly scary machine. And we never find out who built it, what they built if for, or if there are more of them out there somewhere[[note]]Well, we do in the extended universe--it was actually built to take on the Borg--but it is decidedly not canon[[/note]].

* The nightmarish ending of the episode also counts: the Andrea-bot, wielding a laser pistol, utterly at odds with her programming--unsure of whether to love or to kill, embraces her creator, Android!Dr. Korby, prompting him to pull the trigger, disintegrating them both. Kirk and Chapel look on in horror, as do we.

* As Kirk and Bones set out to find the former's friend, they're just walking along... and then out of ''nowhere'', [[JumpScare a Mugato jumps them]], yelling with the most [[HellIsThatNoise terrible, demented screams you could conceive of. And not only is it strong like it's gorilla-like frame implies, it's bite contains a lethal poison, with Kirk getting the full dose before Bones kills it.

* The episode is mostly a lighthearted comedy, but the scene at the end where dead tribbles fall on Kirk until he's standing nearly waist-deep in them is very... disturbing. It's the equivalent of opening the door to the attic and being bombarded with dead kittens, and they just kept falling as Kirk was standing there, probably from being casually tossed aside by [[spoiler: Dax and Sisko]]. And it was played for comedy. ''Twice''!

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that everyone on the planet gets to unleash their repressed emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''; one poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. The situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]'' [[note]]Indeed, the creator of ''The Purge'' took major inspiration from this episode.[[/note]]

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that all these people get to unleash their emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''; one poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. The situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]'' [[note]]Indeed, the creator of ''The Purge'' took major inspiration from this episode.[[/note]]

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that all these people get to unleash their emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''; one poor girl [[ImpliedRape was implicitly assaulted - or worse]] - and is in hysterics the next morning; not even Landru's influence can keep her calm. In practice, the situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]''

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that all these people get to unleash their emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their [[StepfordSmiler eerily-calm-if-friendly demeanor]] from earlier... and that's just the stuff we ''see''; one poor girl [[ImpliedRape was implicitly assaulted]] - or worse - and is in hysterics the next morning; not even Landru's influence can keep her calm. In practice, the situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]''

* Though not clearly explained in-episode, the "Festival" is basically the sole time of the year that all these people get to unleash their emotions and desires. The result is utter pandemonium for 12 whole hours, resulting in the street being thrashed by the people, who are more akin to a mindless frenzied mob than their eerily-calm-if-friendly demeanor from earlier... and that's just the stuff we ''see''; one poor girl was explicitly assaulted - or worse - and is in hysterics the next morning, where not even Landru's will can keep her calm. In practice, the situation isn't dissimilar to that of the ''[[Film/ThePurge The Purge...]]''

* The AdultFear, where Bones has to get Nona (who drugs men to do what she says) to save a dying Kirk. The instant she tells him that Kirk belongs to her now, he starts worrying, and even more when Kirk is in denial. It all comes off like watching your friend go into an abusive relationship for a while.

* Also the more AdultFear. Everything the Platonians try to manipulate Bones, Kirk and Spock with, is straight out of the abuse handbook. Kirk gets one line of apology for being “used” after made to slap himself followed by a HurricaneOfExcuses for a bad temper, they all get gifts in an effort to make them stay, and after Kirk is forced to crawl and Spock cry, Bones is blamed for the Platonians doing this to them.

* The idea that a seemingly immortal being had been possessing and killing people for thousands of years just to feed on their fear. The episode itself [[ValuesDissonance hasn't exactly aged well]], but the aforementioned premise remains terrifying to this day.

* [[FridgeHorror The fact that Scotty]] ''[[FridgeHorror just might]]'' [[FridgeHorror have committed those murders while possessed by Redjac.]]
* Redjac has taken over the ship and could easily kill everyone on board, but he wants to frighten all of them first by laughing maniacally while telling them in gruesome detail what he wants to do. To add to this, he's played by John Fiedler, better known as the voice of [[Franchise/WinnieThePooh Piglet]]. Hearing ''that'' voice laughing while screaming "Die! Die!" just might kill your childhood.

[[AC:[[Recap/StarTrekS1E17TheSquireOfGothos The Squire Of Gothos]]]]

* The episode is famously goofy in a charming, campy way, so it's easy to overlook the terrifying nature of the entire dilemma with Trelane. Consider the basic idea of the episode, a [[RealityWarper reality-warping]] [[SpoiledBrat spoiled brat]] who's totally [[BloodKnight obsessed with death and warfare]] and has [[SoreLoser never learned how to lose]] wants to play with you, in his own twisted definition of "play" that may involve freezing you in place, teleporting you out to his personal [[DeathWorld death world]] as punishment, and then deciding to kill you just because of how fun it'd be. And you can't run away, because he'll simply teleport his planet into your way whenever you try, or just teleport you back. The entire episode is basically Charlie X [[UpToEleven Up to Eleven]] in almost every way, only with an added childish bloodlust.

* The whole episode is meant to be scary, being essentially a GothicHorror story [[RecycledInSpace in space]], but those three witch faces that appear out of nowhere are beyond mildly creepy.