[[quoteright:287:[[Series/StarTrekVoyager http://static.tvtropes.org/pmwiki/pub/images/SulanDurstsFace_8843.jpg]]]]
[[caption-width-right:287:[[OrganTheft A face freshly pilfered off your shipmate]] is a [[http://memory-alpha.org/wiki/Vidiian Vidiian's]] idea of AFormYouAreComfortableWith.]]

->''"Space is disease and danger wrapped in darkness and silence."''
-->--'''Doctor Leonard "Bones" [=McCoy=]''', ''{{Film/Star Trek}}''

Generally speaking, where British kids had ''Series/DoctorWho'', American kids had ''Franchise/StarTrek''.

'''Note:''' please avoid [[Administrivia/ConversationInTheMainPage personal examples, anecdotes and natter]]. Feel free to tell us about how scary the Borg are, but we don't need to know how they made you hide under the bed.

!!Television Series:
* NightmareFuel/StarTrekTheOriginalSeries
* NightmareFuel/StarTrekTheNextGeneration
* NightmareFuel/StarTrekDeepSpaceNine
* NightmareFuel/StarTrekVoyager
* NightmareFuel/StarTrekEnterprise

* NightmareFuel/StarTrekTheMotionPicture
* NightmareFuel/StarTrekIITheWrathOfKhan
* NightmareFuel/StarTrekIIITheSearchForSpock
* NightmareFuel/StarTrekFirstContact
* [[NightmareFuel/StarTrek2009 Star Trek (2009 film)]]
* NightmareFuel/StarTrekIntoDarkness


[[folder:The Movies]]
* ''Film/StarTrekVTheFinalFrontier'': The [[JerkassGod jerkass]] EnergyBeing with near-divine powers that was thrown in as its BigBad. That nearly killed Kirk. Then we have its VillainousBreakdown...
* ''Film/StarTrekVITheUndiscoveredCountry'':
** After the Klingon moon explodes in a massive PlanarShockwave, the USS ''Excelsior'' is close enough to not only have to ride out the shockwave, but when they scan the moon, they learn that ''[[EarthShatteringKaboom most of it is now simply not there anymore]]''. They then receive one of the more disturbuing {{Distress Call}}s in the history of the franchise, a Klingon, surrounded by flames, screaming in panicked Klingon before the signal abruptly cuts off, followed by a Klingon officer tersely messaging them to tell them that there has been [[DeadlyEuphemism an accident]], and that Starfleet's assistance is ''not'' required.
** The attack on Gorkon's ship, from the Klingons' point of view. The ''Enterprise'', sent to escort them into Federation space for peace talks, unexpectedly opens fire on them, crippling them and knocking out the ArtificialGravity. Two [[FacelessMooks space-suited assassins]] beam aboard and begin [[ImplacableMan slowly and methodically]] marching through the ship, shooting helpless crewmembers as they float in freefall, unable to fight back or seek safety. Once they find their target, they shoot him in the heart, before calmly marching back the way they came and beaming back to their ship. Did we mention that, due to the lack of gravity, the Klingons' blood is left to ''float'' in blobs drifting through the air, trailing behind the wounded or dead crewmembers, in a rare exception to the BloodlessCarnage usually seen on ''Star Trek''?
** Also, the same attack, from the ''Enterprise'' crew's point of view. The ship they are escorting is being attacked, and by all indications, it was the ''Enterprise'' that did it, with the bridge crew and Mr. Scott urgently shouting at each other unable to agree on what their own conflicting comptuers are telling them, trying to figure out just ''what the hell is going on'' before the Klingon ship finally regains control and prepares to [[ThisMeansWar open fire on them in evident self defense.]]
*** When the Klingon battlecruiser recovers and comes nose-to-nose with the unshielded ''Enterprise'', the ship locks photon torpedos and prepares to fire. Kirk just stares, slack-jawed at the view screen for a full ten seconds. This is the first time in the history of Star Trek that we've seen Kirk [[OOCIsSeriousBusiness falter in the command chair]]. He doesn't order shields up, he doesn't order evasive maneuvers, and he doesn't charge weapons, or anything else we expect him to do. He just sits there, staring. . .and then he surrenders. It's terrifying.
**** What sells that part is the rest of his crew's reaction, ''especially'' Valeris', you know, an emotionless Vulcan.
---->Chekov: "Shields Captain?"
----> (beat)
---->Chekov: "Shields ''UP'', Captain?"
----> (beat) (Klingon Cruiser is now at point-blank range filling the viewscreen, torpedoes armed)
---->Valeris: (with barely contained terror) " '''''Captain! OUR SHIELDS!''''' "
** A bit of a fridge example: Since the 1960s, the phaser has represented a sort of holy grail in less-than-lethal weapon engineering; with their ability to subdue an individual ''or'' a crowd instantly with no noticeable lasting health effects. This film, however, makes a plot point of the fact that even phasers on stun are potentially deadly.
* ''Film/StarTrekInsurrection''. The flesh stretching process of the Son'a. Only somewhat Nightmare Fuel until head baddie Ru'afo [[spoiler:betrays Admiral Dougherty, killing him by subjecting him to a flesh stretching machine. Ow.]]
* ''Film/StarTrekGenerations''. When Data's newly-installed emotion chip overloads and he goes LaughingMad, it's ''creepy as hell.''
** Picard's family including Jean-Luc idolizing, CheerfulChild René--one of the very few children that Picard likes--[[spoiler: dying in a goddamned fire.]]
** After [[spoiler: Picard fails to stop Soran the first time and they're sucked into the Nexus]], it winds up destroying the planet they're on. And it just so happens to now include [[spoiler: everyone inside the crashed saucer section of the Enterprise. Which means every character we've come to know and love for the past seven years--- Riker, Data, Beverly, Troi, Worf--- ''they're [[KillEmAll all dead]]''. We even get to see some survivors crawling out of the ship's remains just as the planet explodes for good measure.]]

[[folder:New Voyages]]
* "Blood and Fire" is about Regulan bloodworms. The ones the Klingons were joking about in "The Trouble with Tribbles". Regulan bloodworms are not funny. Or cute. Or harmless and useful, like the ones in ''Enterprise''. Point of fact, [[spoiler: they travel in gigantic swarms, and they eat people alive, and we get to see it.]]
** Even the Klingons are clearly terrified of them.