Summary

• Time loop stories are a classic science fiction premise Star Trek excels at.
• Star Trek: Enterprise and Voyager had excellent time loop episodes, but The Next Generation's "Cause and Effect" is the best.
• Star Trek: Discovery had two time loop episodes, "Magic to Make the Sanest Man Go Mad" and "Face the Strange".

Time loop stories are a classic science fiction premise, and Star Trek has dipped into that well several times. Although Star Trek: The Original Series never did a traditional time loop episode, plenty of Captain James T. Kirk's (William Shatner) adventures involved time travel. Every Star Trek series since has incorporated time travel in some way, including two of the franchise's most highly regarded films, Star Trek IV: The Voyage Home & Star Trek: First . Not every Trek series has done a time loop episode, but it's an incredibly fun premise that makes for great television when it's done well.

The time loop premise fits so well within the world of Star Trek, that it makes sense the franchise would return to it multiple times. Time loops (or "temporal causality loops") are apparently so common in the Star Trek universe, that Starfleet uses a time loop simulation as one of their training drills. In Star Trek: Lower Decks season 2, episode 8, "I, Excretus," a holodeck simulation called "Time Loop" was one of the possible drills the USS Cerrtos' Lower Deckers had to run, along with things like infiltrating a Borg cube or escaping the Mirror Universe. Being a Starfleet officer means being ready for anything, and here are five Star Trek episodes that trapped their characters in a time loop.

Many television shows have taken advantage of a time loop premise, with Stargate SG-1, Buffy the Vampire Slayer, The X-Files, and Supernatural all delivering particularly fun time loop episodes.

5 "Future Tense"

Star Trek: Enterprise Season 2, Episode 16

Although not a time loop episode in the traditional sense, Star Trek: Enterprise's "Future Tense" features two different miniature time loops. When the Enterprise NX-01 finds a derelict shuttlepod from the future floating in space, the temporal radiation leaking from the ship causes time disturbances. As Commander Trip Tucker (Connor Trinneer) and Lt. Malcolm Reed (Dominic Keating) continue to examine the shuttlepod, they find themselves reliving the same moment over and over.

"Future Tense" has some fun moments, including the time loops.

Captain Jonathan Archer (Scott Bakula) and Sub-Commander T'Pol (Jolene Blalock) discover that the pod is from the 31st century and presume it must be connected to the Temporal Cold War in some way. To keep the pod from the Suliban or the Tholians, Archer and Reed try to booby-trap it but end up stuck in another time loop. Eventually Trip activates the pod's distress signal and the ship vanishes, presumably back to the 31st century. "Future Tense" has some fun moments, including the time loops, but the Temporal Cold War storyline on Enterprise never quite worked as well as it could have.

The 31st-century shuttlepod is impossibly bigger on the inside than the outside, a nod to the time-traveling TARDIS on Doctor Who.

4 "Coda"

Star Trek: Voyager Season 3, Episode 15

When a shuttlecraft carrying Captain Kathryn Janeway (Kate Mulgrew) and Commander Chakotay (Robert Beltran) crash lands on a planet, Janeway is seriously injured. Before long, Star Trek: Voyager's villains the Vidiians find the crashed shuttle and kill Janeway and Chakotay. The two then appear again on the shuttle just before they crashed. Immediately realizing they're caught in a time loop, Janeway and Chakotay try something different, but this time, their shuttle explodes. Time resets again, and Janeway and Chakotay make it back to Voyager before Janeway is killed again.

"Coda" is an entertaining and even frightening episode, and Kate Mulgrew delivers a great performance.

In the final loop of Star Trek: Voyager's "Coda", Janeway sees herself "die" and encounters the supposed spirit of her father. Realizing that something isn't right, Janeway refuses to go with him and wakes up on the planet as Chakotay and The Doctor (Robert Picardo) revive her. "Coda" is an entertaining and even frightening episode, and Kate Mulgrew delivers a great performance. However, the final reveal that most of the story happened in Janeway's head undercuts some of the more emotional moments.

3 "Magic to Make the Sanest Man Go Mad"

Star Trek: Discovery Season 1, Episode 7

Star Trek: Discovery season 1 received a mixed reception from fans, but "Magic to Make the Sanest Man Go Mad" stands out as a solid and entertaining take on a classic premise. When Harry Mudd (Rainn Wilson) arrives on the USS Discovery, he enacts his plan to kill Captain Gabriel Lorca (Jason Isaacs) and sell Discovery's spore drive technology to the Klingons. Mudd has a time crystal that allows him to repeat the same 30-minute time period over and over.

Victorious, Burnham delivers the coup de grâce line to Mudd: "Turns out you can con a con man."

Due to the tardigrade DNA in his system, Lieutenant Paul Stamets (Anthony Rapp) remains aware of the time loops, and he recruits Michael Burnham (Sonequa Martin-Green) and Lt. Ash Tyler (Shazad Latif) to help him stop Mudd. Mudd kills Lorca repeatedly and nearly succeeds in his plan, but Stamets, Burnham, and Tyler reroute Mudd's signal to his fiancée, Stella (Katherine Barrell), and her father rather than the Klingons. Victorious, Burnham delivers the coup de grâce line to Mudd: "Turns out you can con a con man."

2 "Face the Strange"

Star Trek: Discovery Season 5, Episode 4

In one of Star Trek: Discovery's best episodes so far, Captain Burnham and her new First Officer, Commander Rayner (Callum Keith Rennie), find themselves jumping through different time periods in Discovery's past, present, and future. Like the previous time he was stuck in a time loop, Stamets remains aware of the jumps and works with Burnham and Rayner to find a solution. They revisit multiple moments from past seasons of Discovery, and Michael even encounters her past self, resulting in a Burnham vs. Burnham fistfight.

The time jumping turns out to be the result of a Krenim "time bug" that courier Moll (Eve Harlow) snuck onto the Enterprise in the previous episode.

Burnham and Rayner also get a glimpse of a possible future where the Breen ended up with the Progenitors' technology and destroyed the Federation. Thankfully, Stamets, Burnham, and Rayner prevent this future by destroying the time bug, and Discovery loses only six hours rather than the weeks it could have lost. Not only is Star Trek: Discovery season 5, episode 4 an incredibly fun episode of Star Trek, but it also shows how far Burnham and the other characters have come since the show's first season.

1 "Cause and Effect"

Star Trek: The Next Generation Season 5, Episode 18

In Star Trek's first true time loop episode, the USS Enterprise-D is destroyed over and over again as Lt. Commander Data (Brent Spiner) and the rest of the crew try to find a solution. After a cold open that ends with the Enterprise blowing up, the crew end up back at their game of poker. Although they do not initially realize they are stuck in a time loop, Dr. Beverly Crusher (Gates McFadden) begins experiencing a sense of déjà vu. After they discover their predicament, Data sends a message to himself using his positronic brain.

Wonderfully directed by Jonathan Frakes, every time loop in "Cause and Effect" feels unique.

At the end of each loop, the Enterprise collides with another ship as it emerges from a space-time distortion, after Data's suggestion to use the tractor beam fails. Data eventually realizes the message he sent himself indicates they should try Commander William Riker's (Jonathan Frakes) suggestion to decompress the main shuttlebay. The plan works and the Enterprise finally avoids the collision. Captain Jean-Luc Picard (Patrick Stewart) then s the other ship, the USS Bozeman, which has been missing for over 90 years. Wonderfully directed by Jonathan Frakes, every time loop in "Cause and Effect" feels unique, and the episode remains one of Star Trek's most memorable time travel stories.

Star Trek: The Next Generation, Star Trek: Voyager, Star Trek: Enterprise, & Star Trek: Discovery are all available to stream on Paramount+.