During its unparalleled 55-year run on the big and small screen which continues to this day, Star Trek and its various iterations and offshoots have provided viewers with countless thrills and chills. Yet, when Star Trek is often brought up, the horror genre is the last thing to spring to mind. Instead, the campiness of William Shatner and his fellow Trekkies' intergalactic adventures offer entertainment the whole family can enjoy.
However, die-hard Trekkies know that the Star Trek canon has been fraught with more than a handful of truly terrifying episodes over its six-decade run on the air. For the absolute most frightening, scroll below.
Catspaw - S2E7
Scripted by Pscyho screenwriter Robert Bloch, "Catspaw" from the Original Star Trek series is one of the most overt attempts at scaring the audience in series history.
Festooned with macabre black cats, spooky witches, moldering castles with cobwebs, spiders, skeletons, and other familiar Halloween iconography, the episode finds the crew in the hypnotic hold of an alien wizard name Korob and his witchy minions. The aliens try to infiltrate the Enterprise and subsume the crew, but Kirk and Spock thwart their nefarious plot.
Genesis - TNG S7E19
In The Next Generation's episode "Genesis," the show courts the conventions of a monstrous creature-feature in ways even Guillermo del Toro's biggest fans would appreciate. The episode concerns Barclay receiving an inoculation of synthetic T-cells that have horrifying consequences.
Upon Barclay's injection, the entire crew begins acting strange. Worf begins drooling toxic venom, Troi morphs into a monstrous mutation akin to the Fish Man, and, most frightening of all, Barclay transmutes into a giant spider that almost gives Picard a heart-attack.
The Thaw - Voyager S2E23
"The Thaw" is one of Star Trek Voyager's most chilling and petrifying episodes to date. Michael McKean plays a creepy clown from outer space who tortures Kim to no end.
When The Enterprise lands on an icy planet to find three strange entities in a stasis chamber, Kim and Torres investigate. Their search leads them into a virtual reality where the manifestation of fear itself materializes in the form of a horrifying clown. As the Voyager races to rescue Kim, Torres, and the three static entities, The Clown wreaks freaky havoc.
Empok Nor - DSN S5E24
In an episode that calls to mind the best of the Alien franchise, Empok Nor is one of the most unsettling Star Trek episodes of all time. The story finds O'Brien and his DSN crew on a mission to salvage Cardassian equipment left behind at their sister space station.
When the crew arrives at the abandoned station, they discover dead bodies hanging from the walls. As they advance further, the crew realizes that they're in the middle of a lethal booby trap designed to kill them, one by one. The dreadful haunted-house atmosphere atones for the lack of physical monsters.
Wolf In The Fold - S2E14
Also written by Psycho's Robert Bloch is "Wolf in the Fold," a hair-raising episode from the original Star Trek series. The story launches when Scotty is accused of murdering a stripper while on shore leave. However, Scotty has no recollection of the incident even after being found by the body with a bloodsoaked knife in tow.
Upon further investigation, it turns out that a malefic spirit once-known as Jack the Ripper has possessed the Enterprise computer, taken over Scotty's body, and continued his kill-crazy rampage.
Impulse - STE S3E5
Just prior to zombies making a torrid comeback on the big and small screen via Dawn of the Dead, Shaun of the Dead, and The Walking Dead, Star Trek Enterprise dished a bone-chilling and bloodcurdling episode of reanimated corpses.
Impulse finds the Enterprise crew dispatched to a marooned Vulcan ship, only to be met by a vicious horde of bloodsucking ghouls running roughshod over the barren vessel. Blamed on a neurotoxin called Trellium, the flesh-starved drones attack the Enterprise crew until a Trellium-rich antidote can be formulated.
Night Terrors - TNG S4E17
In addition to being one of the most psychologically arresting episodes, Night Terrors features the single scariest scene in the history of the series. When the Enterprise crew gets stuck in a fourth-dimensional rift, they begin experiencing eerie hallucinations and deep-seated paranoia.
The scariest scene comes when Dr. Crusher investigates a morgue alone and all of the dead bodies in the room sit upright in unison without making a single sound. Guaranteed nightmare fuel!
Conspiracy - TNG S1E24
"Conspiracy" is by leaps and bounds the goriest and most gruesome episode of Star Trek ever produced. The story concerns Picard and Riker attempting to quash an alien parasite that finds its way on board The Enterprise.
With graphic imagery ripped right out of a Lucio Fulci movie, the episode culminates with a bloody and grotesque parasite chewing through the sternum of an unnamed Commander. Sliterhing parasitic worms, detonated heads, and an underlying sense of paranoid dread make "Conspiracy" an all-time Star Trek frightener.
Frame Of Mind - TNG S6E21
With a sterling 8.3/10 IMDB rating, "Frame of Mind" is one of the highest-quality spook-stories in the exhaustive Star Trek canon. The episode finds Riker questioning his sanity when trapped in a maddening extraterrestrial psych-ward.
The head-spinning Twilight Zone-like story beats, batters, and bruises viewers into psychological submission as Riker tries to pin down what is real and what is phantasmagoric projection. With a great performance by Jonathan Frakes, "Frame of Mind" is true terror incarnate.
Schisms - TNG S6E5
According to the most knowledgeable Trekkies and horror experts alike, the single scariest episode of Star Trek belongs to "Schisms," the fifth frame of The Next Generation's sixth season.
Schisms picks up when some of the crew members complain about the lack of sleep. Plagued with a vague sense of deja vu, Riker becomes frightened by regular objects aboard the ship. Upon further inspection, the crew realizes they've all been part of a collective abduction experiment by a mysterious race of aliens. The escalating tension, suspense, and unease culminate in bone-clattering chills.