Fans are settling aboard the original Enterprise to enjoy Captain Pike’s galactic adventure in Star Trek: Strange New Worlds. The new series has been a pleasant return to classic Star Trek storytelling, though some fans are waiting for dark times to hit as well. Star Trek: The Next Generation taught fans of the franchise that something terrible is always just around the corner.

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The crew of the Enterprise-D from Star Trek: TNG encountered quite a few powerful beings and deadly situations that put them at risk on more than one occasion. The series featured memorable deaths and pushed the boundaries as the crew dealt with some of the worst situations the final frontier of space had to offer.

10 Lt. Tasha Yar Was Killed By A Deadly Evil Being While On An Away Mission

Tasha Yar from Star Trek The Next Generation

The first season of Star Trek: The Next Generation made history in the franchise. “Skin of Evil” featured the first death of a series regular that wasn’t undone in some way. One of Star Trek: TNG's best away teams encountered a powerful being known as Armus who was holding Counselor Troi prisoner in a crashed shuttle.

Lt. Yar was on the away mission as Security Chief of the Enterprise when she was struck down by Armus as a display of his power. Her death greatly affected the crew of the Enterprise and would have lasting repercussions that would be explored throughout the series. While Yar was the only one hurt, it still stands as one of the worst things to happen to the Enterprise-D.

9 The Enterprise-C Was Forced To Return To The Past And Face Their Deaths

The crews of different Enterprises from Yesterday's Enterprise split image

More than one Enterprise made an appearance on Star Trek: TNG over the course of the series. The modern ship met the crew of the Enterprise-C when they appeared from a temporal rift in the third season’s “Yesterday’s Enterprise.” The Enterprise-C’s journey through time during one of Star Trek's greatest battles altered the timeline and placed the Federation at war.

Lt. Tasha Yar returned in the new timeline as the Security Chief of a weaponized version of the Enterprise-D. After learning the timeline had been altered, the crew of the Enterprise-C made the decision to return through the rift and face their deaths in the battle to save the timeline. Yar decided to join the Enterprise-C to face a better death that successfully reset the timeline.

8 A Young Ensign Was Lost On An Undercover Mission Into Cardassian Space

Ensign Sito Jaxa and a Cardassian from Star Trek TNG's Lower Decks

There were a number of important events that affected the entire crew of the ship. However, the seventh season’s “Lower Decks” episode showed how much one person’s death could affect the other crew members on the Enterprise. Struggling to recover from a tragedy during her academy years, young Ensign Sito Jaxa and her friends worked to move up through the Enterprise’s ranks.

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Jaxa was being pushed hard by her commanding officers and the captain. She was asked to go on a dangerous undercover mission to help return a Cardassian spy to enemy territory. Hoping to prove herself to Captain Picard, Jaxa accepted the mission. She was tragically killed during the plan, leaving her friends and the senior officers involved left to grieve and question their decisions.

7 The Crew Nearly Died From Sleep Deprivation After They Were Trapped In A Rift

Worf and Troi from Star Trek TNG's Night Terrors

The fourth season’s “Night Terrors” followed the Enterprise’s mission to find a missing Federation ship. They found the derelict ship filled with a deceased crew but were soon caught in a spatial phenomenon. While stuck in the rift, the crew was unable to enter into the restorative REM sleep cycle, leading to extreme deprivation.

The crew’s attitude and ability to perform grew worse and threatened to cause fatal accidents or mental breakdowns as their bodies shut down. Counselor Troi used her dreams to telepathically connect with a ship on the other side of the rift. She was able to coordinate an attack with Lt. Cmdr. Data that managed to free both ships and save the crew before they were wiped out.

Captain Riker from an alternate reality in Star Trek TNG

Lt. Worf found himself drifting between different parallel realities after he was thrown into a quantum flux in the seventh season’s “Parallels.” This quantum break threatened to destabilize and destroy these parallel realities, leading to a meeting of different versions of the Enterprise at the anomaly. One of those ships featured a Captain Riker from a dark reality overrun by The Borg.

Fans never learned too much about the terrifying alternate reality. However, it was enough to drive the tormented Captain Riker of that reality’s Enterprise-D to turn on the other starships that had appeared at the temporal rift. He would have rather destroyed the multiverse than go back to his timeline, which said a lot about what the dilapidated crew went through in that universe.

5 The Enterprise Was Repeatedly Destroyed After It Was Caught In A Temporal Loop

The Enterprise exploding in Cause and Effect

Star Trek: TNG explored more than a few temporal anomalies across seven seasons of the series. “Time Squared” from the second season saw the crew attempt to avoid the destruction of the Enterprise after finding another Captain Picard who was sent back six hours in time. The crew of the Enterprise suffered even more in the fifth season’s “Cause and Effect.”

The Enterprise discovered it was caught in a “temporal causality loop” after experiencing repeated events. The loop always ended with the destruction of the Enterprise due to a collision with another ship as Captain Picard was forced to choose between two courses of action. The Enterprise was destroyed at least 16 times before they were able to escape the loop unharmed.

4 They Were Transformed Into Ancient Animals By A Mutated Synthetic T-Cell

Worf transformed in Star Trek TNG's Genesis

“Genesis” from the seventh season saw the crew of the ship infected with a usually harmless T-Cell that had been administered to Lt. Barclay by Dr. Crusher. However, it began to mutate and spread among the crew, transforming them into primal animals whose DNA was stored in their genetic makeup.

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Some members were safely locked away for their transformations. Cmdr. Riker de-evolved into a caveman and Counselor Trio became an amphibian. However, some members of the crew were viciously murdered by Lt. Worf, who had become a feral Klingon beast. Data and Captain Picard returned to the ship after the transformations had taken place, and they were able to create a cure.

3 Members of the Crew Were Abducted And Experimented On By Subspace Aliens

Riker being experimented on by aliens in Star Trek TNG's Schism

Members of the crew like Cmdr. Riker and Lt. Worf began to experience moments of lost time in the sixth season episode “Schisms.” This was coupled with bizarre medical findings of experimentation that they didn’t remember. Cmdr. Riker’s arm had been cut off and reattached, while others had experienced similar events.

They were able to piece their shared experience in one of the best episodes involving the holodeck. It was soon revealed that members of the crew were being secretly abducted by subspace aliens for dangerous experimentation. One of the abductees had his blood replaced which led to his death before they were able to seal off the subspace connection to the mysterious aliens.

2 The Crew Was Almost Fatally Experimented On By An Other-Dimensional Being

Nagilum and Ensign Haskell from Star Trek TNG

The Enterprise encountered a powerful and curious other-dimensional being named Nagilum in the second season’s “Where Silence Has Lease.” The crew found themselves trapped after investigating what appeared to be a hole in space. They soon discovered they were being tested by one of the most dangerous enemies from Star Trek: TNG named Nagilum.

Nagilum’s curiosity proved dangerous when he discovered the concept of morality by killing Ensign Haskell on the bridge. Nagilum hoped to further test the limits of the human body by killing about half of the ship’s population as an experiment. Capt. Picard and crew were able to bluff their way out by threatening to self-destruct the ship and ending his experiment prematurely.

1 They Were Put On Trial By The Q Continuum Who Decided To Judge The Human Race

Q from Star Trek: The Next Generation

“Encounter at Farpoint” was the first episode of Star Trek: TNG which also served as the debut of the omnipotent being known as Q. He gathered the senior officers of the Enterprise together in a barbaric human trial from the past. The Q Continuum had decided to put the human race on trial for their past failings, with the possible sentence being the eradication of the species.

Captain Picard's best quotes appeared to win over Q. However, the seventh season finale “All Good Things” revealed that the trial had never ended, and the Q Continuum had been watching Picard and the Enterprise in their continuing judgment. It was an unfair responsibility heaped on Picard that placed not only his crew but also the rest of humanity at great risk.