In Spite Of A Nail / Live-Action TV

Strangely similar timelines in live-action TV.

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• 12 Monkeys: At the end of the pilot, Cole successfully kills Jeffrey Goines in 2015, but this has no effect on the future, as his work is continued by others — most likely, the titular 'Army of the Twelve Monkeys'. Of course, it's also possible that Jeffrey Goines was never the one directly involved in the creation and release of the virus, which would void this trope.
• Babylon 5: In "War Without End", we see the Ivanova of a timeline where Sinclair and Babylon 4 never went back in time recording a message before Babylon 5 blows up. She's wearing the uniform that Delenn had made for her. But in this timeline, because Sinclair didn't go to the past, Delenn wouldn't have been born, because she's Sinclair's descendant.
• Buffy the Vampire Slayer:
  • In the alternate universe of "The Wish", Giles somehow got to Sunnydale despite Buffy's not being there and Giles not knowing that Buffy was supposed to be there, even though his sole reason for coming to the town in the normal timeline was to find Buffy and become her mentor. Cordelia questions this, but is killed before we can get an explanation.
  • Less bothersome with the other characters, because they all lived in Sunnydale independently of Buffy, and the divergence point was only about three years earlier. Which brings up an interesting general rule: The further back in time the divergence point is, the weirder In Spite of a Nail becomes.
• Chousei Kantai Sazer X: Despite all the minor changes both Sazer-X and Neo Descal make to the past, the future stays the same and cannot be altered unless one of Descal's Three Shoguns or one of their future descendants is killed, as the Neo Descal are descended from them. It's implied this is due to the wish the Three Shoguns made with the Cosmo Capsules in the original timeline influencing things across time and space, as the rise of Descal cannot be undone unless a new wish is made with the Cosmo Capsules that undoes the previous wish.
• On Continuum, the time-space continuum is described as being extremely self-correcting and that most of the time even a Grandfather Paradox will not affect the major events of the timeline. In addition, a group of fanatical Time Police make sure that time travelers are stopped before they can do any real damage and that any significant changes are corrected. All of this ends up being subverted when a major historical figure travels back in time a week to change a major event in his own life and then sticks around to interact with the other time travelers already present in that time period. This is too much of a paradox and a Time Crash occurs where the entire future timeline is wiped out and a brand new timeline is created to account for all the changes.
• Doctor Who:
  • In "Inferno", the Doctor borrows power from the Inferno Project to jump-start the TARDIS and winds up in an Alternate History where Britain has been a fascist dictatorship for decades — but there's still an Inferno Project (though the alternate versions are closer to completing their project), run for the same purpose by the same people (although, again, not always in the same roles). Which is convenient, since he needs to borrow power from them again to get back home.
  • In "Father's Day", Rose's father died alone in a hit-and-run accident when she was a baby. She goes back in time and saves his life instead. This creates a Temporal Paradox and prompts the Clock Roaches to start eating people. Her father ends up setting things right by throwing himself in front of the car that was supposed to have killed him, but this time Rose is there and comforts him while his life slips away, thus altering her own past in a trivial way that doesn't affect the greater march of time. This also affects the driver, as the accident is no longer a hit-and-run.
  • "Rise of the Cybermen": The Doctor, Rose, and Mickey visit an Alternate Universe where history is different enough that Britain has a black President (yes, president, not prime minister) and a thriving zeppelin industry — but Mickey was still born and lives at the same address (though he's named "Ricky" and implied to be gay, and his grandmother is still alive). Both of Rose's parents also exist in this universe under the same names, and were still married, although Rose herself was explicitly never born (with a dog taking her place) and Pete never died in the eighties. While they originated on a planet known as Mondas in the main universe, this Earth also ends up producing a race of Cybermen that are essentially the same as their counterparts. There doesn't appear to be a Doctor, though, or he's seriously shirking his world-saving duties. Until the series 4 finale, that is.
  • "The Shakespeare Code": Martha is afraid of altering history after landing in Elizabethan London. When bringing up the butterfly paradox, the Doctor says, "Tell you what: Don't step on any butterflies. What have butterflies ever done to you?"
  • "Turn Left": It doesn't matter whether Donna turns left because she's being stubborn, or because there's a traffic jam caused by a mysterious doppelgänger of her who ran into traffic. The correct timeline will be restored anyways.
  • In "The Waters of Mars", this takes a darker turn as the Doctor attempts to break the laws of Time in order to save someone that history says should have died. Despite his efforts, or rather because of them, she commits suicide, and history is altered but still preserves the key elements that cause the future to occur as it should. Among the altered events is the survival of two other people who should've died, and the revelation of what happened on Mars to the world (it was previously a mystery).
  • Played around with in "Vincent and the Doctor"; after helping Vincent van Gogh fight an invisible alien monster, the Doctor and Amy decide to take him to a present-day art gallery that is showcasing his works to cheer him up and show the impact his life will have. Vincent thanks them and goes on his way, after which Amy rushes them back to the gallery to see all the new paintings he came up with... only to find there are none; besides removing the monster from his painting of the church and dedicating his sunflower painting to Amy, nothing had changed and Vincent still killed himself at a young age due to his depression and various mental issues. Two episodes later, it's revealed there was a new painting; one of Vincent's last was a painting of the TARDIS exploding, and his newfound optimism came crashing down with the idea that his best friends died horribly in the future, leading to him committing suicide out of grief.
• The 4th season of Eureka plays havoc with this trope. Five of the main characters accidentally travel to 1947 (the founding of Eureka) and bring the guy responsible for the city back with them to 2010. Specific things have changed while others are completely the same:
  • Allison still had a son, Kevin, by the same father, who looks exactly the same — but is no longer autistic. This one gets lampshaded, with Henry noting that no one knows what causes it in the first place, so it would be impossible to figure out how it changed. Jack hypothesizes that Kevin may have engineered the time travel incident in order to undo his autism, but as he didn't travel back with them he has no memory of ever doing so.
  • Allison is no longer head of GD (Fargo is) — yet she still lives and works in Eureka (as chief medical officer). It's mentioned that Fargo got to this point thanks to the influence of his grandfather. It can be assumed that, in this timeline, Grand-Fargo did not become a Human Popsicle early in his career and rose high in GD.
  • Henry is married to a woman he previously barely knew — yet still has the same garage and equipment and is still mayor of Eureka. Except both of them are members of the Consortium, although Henry doesn't know it, since his alternate self was erased the moment he returned to the present. And Alt!Henry is supposed to have asthma, and he continues taking the medicine while maintaining the ruse for his wife, despite the fact that it could be harmful to someone who isn't an asthmatic.
  • GD is much more of a DoD puppet with Fargo in charge — yet all the same scientists work on all the same projects as before.
  • Jo is no longer deputy and is now chief of GD security, with her replacement being Andy the robot. And due to him never having gone through Character Development, Zane never dated her.
  • Tess never left for Australia, so it is assumed that her relationship with Carter was perfect, and she was even moving in with him.
  • Fargo's girlfriend Jennifer is now rich and married to an astronaut.
  • All of the highly improbable events that occurred in previous seasons are assumed to still have happened, like Nathan being dematerialized by a rogue experiment on his wedding day.
  • Henry uses the term "ripple effect" to explain why little if any history has changed on a global scale: the time travel hit Eureka profoundly like a wave, causing major changes which would have caused other changes - ripples - which would have caused other changes and so on, and affected areas besides Eureka, but the further away from Eureka, the less significant the changes would be, and the ripples would eventually stop.
• This trope is explicit in Farscape. First mentioned in "Different Destinations...", when Harvey tells Crichton that "If nudged closely enough to course, events have a way of restructuring themselves. If the participants are the same, the venue's the same, the motivation's the same, then, well, the outcome is likely to be the same." It's confirmed by the Ancient "Einstein", and soon put to use again when the crew has to fix Crichton's past.
• The Frasier episode "Sliding Frasiers" follows two possible timelines for Frasier in the run-up to Valentine's Day. In one timeline, he accidentally injures his shoulder, has a Meet Cute with an attractive blonde woman, falls madly in love and takes her to the KACL Valentines party; in another timeline he avoids injury and attends the party bitter and alone, while the blonde woman also attends with another man. In the "love" timeline he goes a hundred miles a minute into the relationship as usual, so the woman feels smothered, dumps him at the party and leaves with her boyfriend from the other timeline. In both timelines Frasier drives home alone listening to a repeat of his radio show, then decides to check in on a woman who called in to ask him out, symbolised by the two Frasiers' cars fusing together.
• Friends:
  • Played with in the episode "The One That Could Have Been". It takes a look at the lives of the main six characters had each one had one significant change in their life: Ross never got divorced, Monica never lost weight, Chandler quit his job, Rachel got married, Phoebe became a stockbroker. In the end, by the time it's over most of their lives resemble their ones from the "real" world: Ross realizes his marriage is over while Carol gets together with Susan, Monica and Chandler have fallen in love and got together, Rachel's left her husband, Phoebe's lost her job as a stockbroker and is now performing her usual bizarre songs at Central Perk, etc. The director's commentary lampshades this:
    Kevin Bright: It would have been different, but ultimately it would have been the same.
  • Joey's case is an inversion, as his main "what if?" scenario is he was never fired from "Days of Our Lives" back during the events of the second season, and he's still happily employed as one of the regular cast members by the end of the episode. In the following season after "The One That Could Have Been" after learning some humility he's able to successfully appeal to the creator of the soap and is brought back. Notably, one episode that features a very brief clip from a "Days of Our Lives" episode is actually reused from the one shown in "The One That Could Have Been".
• Fringe:
  • While the exact point of divergence of the two universes is not yet known, it's hard to imagine it could be later than about 1900 and revelations from Season 3 suggest it could possibly predate the dinosaurs. Despite this the majority of characters exist on both sides. In fact, we learn that the Bishops in both universe live in the same house and Peter sleeps in the same bedroom.
  • Barack Obama is president of the United States during the 2009-2013 term in both universes. In one of them, no one has heard of Andrew Jackson, who (in our universe) basically founded the U.S. Democratic Party that Obama belongs to.
  • Examined in the season 4 episode "Everything In Its Right Place", where two versions of Lincoln Lee compare their lives to find out where they diverged into Captain Lee being a hyper-confident badass and Agent Lee being a cautious By-the-Book Cop, and find that their lives were identical, down to every last detail, through high school. The confident version rejects the idea that his personality has to be dictated by his past circumstances, and proposes that he's the way he is because it's what he chose to become.
• In The Good Place's second season, no matter how many times Michael tries to change the Bad Place torture scenario the four leads are trapped in with hundreds of reboots, Eleanor always ends up seeking out Chidi to become a better person and the group always end up growing as people and realizing that they aren't in the Good Place. Eventually, Michael gets frustrated by the failures, and under pressure from his boss, who thinks he's still on his second attempt, strikes a bargain to work with the leads to create the illusion that the torture is working.
• Hercules: The Legendary Journeys had an Alternate Universe ruled by "the Sovereign", the evil version of Hercules. The characters were relatively the same in both worlds due to a psychic link; the link was so strong that if a character dies in one world, this results in the death of their counterpart. Which, given how bloodthirsty the Sovereign was, kinda makes you wonder why people in "our" world weren't dropping dead left and right as he cut down their doppelgangers. It was also later discovered that if you were in the limbo-like realm which connected the two worlds when your counterpart died, you would not be affected. This was how the AU Iolaus was able to survive his counterpart's death and how Hercules was able to survive the Sovereign's death in later episodes.
• Important Things with Demetri Martin: In "Chairs", Demetri goes to a wedding reception, and must decide whether to sit next to an attractive young woman or a Cool Old Guy. We then see the results of both choices: either way, he runs afoul of a guy named Angelo and winds up tied up in a basement with a rat cage strapped to his face.
• Journeyman:
  • The lead character of Dan Vassar, while traveling through time, meets and interacts with his friends and family in the past. This never has any impact on the present day and it seems no one ever asks the Dan in their time about something the time-traveling Dan mentioned to them.
  • In the next to last episode, Dan accidentally makes a change which replaces his son by a daughter, and advances technology to boot. This seemingly averts the trope, because changing the time of someone's conception did have an effect. Yet such a drastic personal and societal change didn't stop him from having the same people visiting him on the same date, his brother getting his girlfriend pregnant at the same time, him having a picture of himself meeting a scientist on the same day, etc. He even meets a psychic in the changed history, and a direct follow-on to that meeting in the fixed history with no indication that things have changed in any way. And the history with the daughter clearly wasn't a Stable Time Loop, either.
  • Rubberband History. It's stated pretty explicitly that there is some sort of intelligence guiding the "Journeys", and that is what keeps everything nearly identical. Likewise, Dan's son becoming a daughter was used because otherwise, what reason would he have to undo the massive technology jump he caused?
• Legends of Tomorrow: History can be changed in minor ways without any effect on the timeline, which is why the Legends don't worry too much about displaying superpowers in the past. Furthermore, occasionally they discover "loopholes" (usually by accident) where major changes can be made without actually having any effect. For example, Helen of Troy has to be kidnapped to start the Trojan War, and trying to change that would rip the universe in half. But as it turns out, once the war has started, her disappearance doesn't have much of an effect, so Zari takes her to Themyscira so that she doesn't just die as a pawn in some meaningless power struggle. Zari eventually writes a program to search for these loopholes in an attempt to fix many of the things wrong with history, but she doesn't always find anything useful.
• This is apparently how the world works in Lost, with one character explicitly stating that "the universe has a way of course-correcting" to make sure that changes to the past don't have any major effects. Although this could be wrong, as we've never seen anything that couldn't be explained as a 100% Stable Time Loop with regard to the actual time traveling. Even an apparent change to Daniel's journal in the past was explained when we learned about his memory problems. Desmond's future flashes, however, do allow him to change the future, but then apparently fate course-corrects back.
  • Frank Lapidus was supposed to be the pilot for Oceanic 815, the plane that crashes at the beginning of the series, but overslept and got replaced by a colleague. In season six he comments on how different his life would be if he'd made the flight, only for Ben Linus to point out that he ended up on the Island anyway so his life isn't actually that different.
• The Lucifer (2016) episode "Once Upon a Time" shows a world where Chloe's father was never killed and thus Chloe was never inspired to be a cop. Instead, she's an actress, Lucifer is still an arrogant club owner, Dan is now a corrupt cop (and as he and Chloe never met, let alone get married, their daughter Trixie doesn't exist); Linda is a talk show host, and more. Yet, when a friend of Chloe's turns up dead in Lucifer's club, the pair manage to end up working together to solve the case. Afterward, Chloe decides she wants to give being a cop for real a try and an intrigued Lucifer offers to help her.
• The Man in the High Castle:
  • In an alternate universe where the Axis powers won World War II, everything in the American Reich is vastly different — except that J. Edgar Hoover is still the highest ranking law enforcement agent.
  • A Cold War still develops between two victorious nuclear powers, but in this case it is the Nazi and Japanese empires rather than the USA and USSR.
• Marvel Cinematic Universe: The Netflix shows take place in a New York City affected by "The Incident", however, evidence suggests that aside from the insertion of the invasion, the city's history has been unaltered. For instance, the Black Lives Matter movement is referenced in Luke Cage (2016). Likewise, Daredevil (2015) shows that the Fall Experimental Football League^note a failed minor league football franchise intent on being a professional feeder system for the NFL; it lasted from 2014 to 2016 still happened, as Karen Page wears a Brooklyn Bolts T-shirt in one scene in season 1. The biggest difference is that the Real Life Hell's Kitchen has escaped its crime and poverty-stricken past and a crime-fighting vigilante would be rather unnecessary, so the Alien Invasion is mentioned as having wrecked much of that area specifically, causing a rise in violent crime and gangsters again so that the story has some reason for being.
  • The seventh season of Agents of S.H.I.E.L.D. relies heavily on time travel, and explicit reference is made to the idea that timelines will naturally self-correct until a sufficiently large change is made to produce a new timeline. An analogy is made to the difference between a stick floating down a river and a beaver's dam redirecting that same river.
• Misfits had an episode where the Nazis won World War II. The characters looked exactly the same, and despite never knowing each other before the events of the series, they had met each other.
• Motherland: Fort Salem: Witches are real. Due to their making a long-ago pact, the US Army has witch soldiers. Women seem to be overall more prominent in US culture as a result, including having a black female President, Kelly Wade.. However, everything else in the US looks just like reality, with the same fashions, modern technology etc (only the military uniforms are different).
• Mud, a BBC live action children's series from the 1990s, ended with the characters returning from a trip back in time and accidentally bringing Christopher Columbus home with them. They go home and everything seems normal, until they try to watch Baywatch — which their mother has never heard of, because the discovery of the Americas must have played out somewhat differently due to his absence. If this was supposed to be a Sequel Hook it fell rather flat, and the viewer is Left Hanging as to whether or not they manage to sort it all out.
• Once Upon a Time: In Season 6 Emma wishes she had never been the Savior and we are shown an alternate Enchanted Forest where Snow White and Prince Charming defeated Regina before she cast the curse. While several things obviously changed (Emma's parents and Hook are now thirty years or so older whereas Pinocchio never changed his name to August) some still stayed the same even though; Robin is still Emma's age, even though he's supposed to be as old as her parents (justified by a side effect of David's wish), Henry is still Emma and Baelfire's son even though Baelfire was supposed to be in Neverland and then escaped to The Land without Magic and Rumpelstiltskin is still Charmings' prisoner, although he had suggested in an earlier episode that he let them capture him and that was part of his plans. These may all be justified by magic.
• Ordinary Joe: Although the three alternate timelines followed by the show are very different from one another, there are a few constants:
  • Joe will somehow cross paths with Congressman Bobby Diaz — as a musician who's married to Diaz's campaign manager, as a cop who saves him from an Assassination Attempt, or as a nurse who cares for him after being wounded in the attack.
  • Joe maintains his love of music no matter his career path.
  • Joe attends his ten-year college reunion in all three timelines.
• Power Rangers
  • In Mighty Morphin' Power Rangers, Kimberly's brief trip to Victorian-era Angel Grove didn't seem to change a thing, despite the fact that Goldar and the Monster of the Week followed her, requiring her to find that era's Zordon and Alpha 5, gain the Power Coins, and give them to the Rangers' great-great grandparents, to fight the villains Ranger-style. (And the present-day Zordon seemed to already know about it. Maybe because it happened already?)
  • Speaking of Power Rangers, the finale of Power Rangers Dino Charge involved the Rangers travelling back to the pre-historic era to defeat Sledge and his shipmates. The result of this involved next to no change in the future Earth aside from the teeny-tiny tidbit of dinosaurs never having gone extinct and co-existing with humans. Such a drastic change ended up being "settled" by stating it was and Alternate Universe just like Power Rangers RPM.
• Primeval:
  • In the 1st series finale, a change in the Permian era, i.e. over a quarter of a billion years ago, erases Claudia from existence while leaving the rest of the team untouched, down to the clothes they are wearing and Stephen still remembering having had an affair with Helen.
  • In season 2 we find out the full extent of the changes: the team has a new base, also Claudia isn't really gone, she just has a different name and personality. This is despite Professor Cutter repeatedly stating that screwing around with history has sent evolution down a completely different path.
  • This issue is actually given as a reason why everyone thinks Professor Cutter has just gone a bit nuts instead of history actually being changed. His response is that there could be many more changes he doesn't even know about.
• Red Dwarf:
  • Hand waved in one episode by specifically erasing Kryten and Lister from history, yet having the two characters still running around trying to not be killed by the guy who erased them. They run into the main characters and find that their "twins" are slightly off and played by completely different people, like the "fraternal brothers" thing only even more distinct than that. Yet the ship still exists, the accident still happened, Dave Lister still managed to be frozen in stasis for three million years, et cetera. Ironically the Robotic Psychopath who erased Kryten and Lister did so specifically because he thought they were wasting their lives, yet their replacements were not different in any significant way at all.
  • "Timeslides" has Dave Lister changing history so that he became a millionaire and never left Earth, prompting the Cat and Kryten to vanish from existence ... yet, bizarrely, Rimmer (who was only revived as a companion for Lister) is still stuck on the ship, 3 million years into deep space.
  • "Tikka to Ride" has the crew accidentally avert the assassination of John F. Kennedy, which results in a Crapsack World future where the US space program, and hence Red Dwarf, never existed ... yet, bizarrely, the crew and their time machine aren't similarly erased from existence. Then there's ... you know what? It's probably best not to think about it.
• The Sarah Jane Adventures: "The Temptation of Sarah Jane Smith" claims that when history gets "diverted", it tries to correct itself, explaining why, in a world enslaved by the Trickster since 1951, Rani's mum still exists and they "happen" to run into her.
• Scrubs: "My Butterfly" shows how the events of a day shift depending on whether the titular butterfly lands on the chest of an attractive woman or an overweight man. It briefly looks as if the "overweight man" scenario will have a happier outcome when J.D. and Cox diagnose their patient sooner, only for him to die in surgery the same way he did in the "attractive woman" version.
• Numerous episodes of Sliders, especially the one where everything was exactly the same except that women had moustaches, and the one where the sky was purple but things were much the same until the Robot War.
  • A Running Gag in early season was that no matter how different each universe was, the protagonists would keep encountering the same sleazy Ambulance Chaser lawyer and Russian cab driver, who had the same jobs in every reality.
  • "In Dino Veritas" is perhaps the biggest of the series. Although dinosaurs survived, none of the featured or mentioned species seemingly evolved in the slightest in the last 65 million years. On the other hand, humans did evolve. Discounting the existence of living dinosaurs being a fact of life on this world and San Francisco being a dinosaur reserve, American society also seems to be largely similar to that of Earth Prime. The poacher is even concerned about being profiled on America's Most Wanted after the ranger discovers him in the dinosaur reserve. When Wade asks the ranger whether she has ever seen anything like the truth collar that she's wearing, the ranger replies, "Yeah, in a Frederick's of Hollywood catalogue."
  • In "Slide Like an Egyptian", the culture of Ancient Egypt survives into the present day and dominates the world. In spite of this, everyone in New Cairo speaks English, a language predominately derived from Latin, the language of The Roman Empire.
  • In "Slidecage", Kromagg Prime diverged from Earth Prime millions of years ago as two sentient species, humans and Kromaggs, evolved on that world. In spite of this, it still has Thanksgiving, Times Square and Beauty and the Beast (1987). Similarly in "Strangers and Comrades", it still has Robin Williams, the Land of Oz books (possibly the many adaptations including the 1939 film too) and Eliot Ness and the Untouchables (again, possibly the television series and the film based upon their exploits as well).
  • Played for laughs in "Time Again and World", in which rock music and anything resembling it didn't progress past the early 60s. Despite this, some musicians we know as rockers still found their way to music, just a much more easy listening form of it. Kurt Cobain has a Christmas album, while Jim Morrison has an album of Irving Berlin covers, which is actually plausible given that his vocal influences were crooners such as Frank Sinatra and Al Jolson, who themselves have performed Berlin's songs.
  • In "Eggheads", intellect is considered such a virtue that popular culture revolves around it and the world's greatest minds are treated like rock stars, yet technology isn't noticeably far ahead of our own world and certain key thinkers' lives seem to have played out the same even though their fields of study would have been more crowded. There's also a rap song that namechecks John Keats, inplying that the genre developed in a completely different cultural context.
• In Smallville, Clark visits a Mirror Universe where the major difference is that he was raised by the Luthors instead of the Kents. His other self was raised to be completely ruthless and evil, but for some reason was still given the first name of Clark.
• Stargate SG-1:
  • In "Moebius, Part 1/Part 2", the team muddles around with Egypt 5,000 years ago. Their admittedly small changes result in a world where the Stargate hasn't been discovered and the main characters aren't quite as cool. Those characters go back and fix things, which results in everything being the way it was before, with the exception of a pond that was but now is no longer devoid of fish (and the sudden existence of a certain lieutenant colonel)...
  • In the episode "The Road Not Taken", there were a few examples:
    • The alternate universe SGC had visited Glastonbury, likely how they drew the Ori to the Milky Way Galaxy, and had imprisoned Vala, but knew nothing about Atlantis. In the main reality, Vala only came to know Daniel and Earth (leading them to Glastonbury) because of when she stole Prometheus, during its attempted mission to Atlantis.
    • Alternate Carter was working on extracting vacuum energy from alternate realities, but in our universe that was based on a technique first attempted by Lantean Ancients, discovered in Atlantis.
    • Alternate Daniel had been captured by the Ori like in the main universe.
    • The alternate versions of McKay and his sister Jeannie likewise have a poor relationship.
• In the Star Trek franchise, this is endemic to the Mirror Universe. After all, for the mirror universe conceit to work, the main characters all require mirror counterparts, no matter how implausible as a practical matter it would be for all those characters to be born, survive to the relevant time, and work together on a counterpart starship/space station.
  • In Star Trek: The Original Series's "Mirror, Mirror", Kirk visits an Alternate Universe where the Federation of Planets is a repressive interstellar empire — but there's still a starship Enterprise, and it has mostly the same crew (although not all of them perform the same functions). Specifically for "Mirror, Mirror", there is a partial explanation in that the mechanism of transfer could only happen between realities in which the same (parallel) people were doing the same thing at the same time.
  • In Star Trek: Deep Space Nine, the Mirror Universe has the station inhabited with largely the same characters, even if some of them are there for vastly different reasons; such as O'Brien, who is (strangely) virtually the same as normal O'Brien (and not, like almost everyone else, evil), and is only on Deep Space Nine as a slave. And yet a later episode explicitly stated that Jake Sisko was never born there. So any future descendants of Jake will not have counterparts there either. This is strange because you'd expect the vastly different MU shown in Kirk's is a strong enough divergence that pretty much nobody in Picard's time exists in the MU; they somehow defy that logic, yet Jake defies the defiance. The most baffling thing is that Vic is still on the station — but isn't a hologram.
  • The Star Trek: Enterprise Mirror Universe two-parter "In A Mirror, Darkly" is similar to the original "Mirror, Mirror" in that the ship mostly has the same crew; the most obvious difference is that Maximilian Forrest (corresponding to Admiral Maxwell Forrest in the main universe) is the Enterprise's captain and Archer is first officer (until he organizes a mutiny and takes over). The Mirror Universe's Dr Phlox looks through the historical records of the prime universe's USS Defiant and notes that the differences between the two universes extend all the way back through Earth's recorded history — with the exception of Shakespeare, whose plays were "equally grim in both universes". Yet this radically different history somehow doesn't prevent the main characters of all the shows from being born except for Jake Sisko.
  • Likewise for the entire mirror universe storyline in seasons 1 and 3 of Star Trek: Discovery: most of the crew has counterparts, even though commanders routinely kill their underlings, the fate that indeed a substantial portion of these counterparts meet on screen. (Mirror Stamets is killed twice.) Unusually, though, in the season 1 storyline, the ship doesn't have its own counterpart: the mirror Discovery crossed into the prime universe and was promptly destroyed in the Klingon War. Instead, the scenes are set in Emperor Philippa Georgiou's massive palace ship. (The season 3 episodes indeed take place on the mirror Discovery prior to its destruction.)
• Star Trek: The Next Generation:
  • In the episode "Yesterday's Enterprise", history changing so that the Federation has been at war with the Klingons for the past twenty years has no apparent effect on the Enterprise's command roster except for the absence of Worf and Troi and the survival of Tasha Yar. It does affect the rest of the ship's complement, though, as instead of nominally carrying 1,014 in Starfleet personnel, civilian crews, families, and passengers, it was a militarized ship capable of carrying 6,000 troops, and the only observed civilian on board was Guinan. (Seventeen-year-old Wesley Crusher was still there but as a fully commissioned officer, when his "main" counterpart was still an acting ensign.)
  • Lampshaded in the episode "Tapestry". Picard becoming a paper-pusher assistant astrophysics officer instead of a legendary starship captain had no apparent effect on the rest of the crew roster (except perhaps Dr. Crusher^note Then again, because Picard didn't become captain of the USS Stargazer, it's possible that Jack Crusher survived and Beverly is with him elsewhere), but that was specifically because of Q's promise to Picard that anything he does in the past will not affect anyone else in the present. It's not at all clear that this is actually how things would have played out if Picard had truly failed to become the captain he was.
  • Zig-zagged in "Parallels", which has Worf going through several dimensions; while Enterprise remains mostly the same, the changes keep mounting to the point where, in the final alternate universe, Wesley was the tactical officer, Picard died during the events of "The Best Of Both Worlds" (leaving Riker as captain), and Troi had married Worf. They also ran into a Riker from a universe where the Borg had conquered the Federation.
  • In "Cause and Effect", the Enterprise is trapped in a "Groundhog Day" Loop that ends with the ship and crew being destroyed. In each loop, Doctor Crusher hears disembodied voices while alone in her room - sounds from the previous loops bleeding into her reality - which startle her enough for her to accidentally knock a glass off her nightstand and have it shatter on the floor. As the loops continue and she becomes more consciously aware of what's going on, Crusher begins to make a conscious effort to not break the glass. But no matter what happens, that glass is doomed to fall and break in some way.
• Star Trek: Strange New Worlds explains that the Eugenics Wars have been moved from the 1990's to the 2030's-2040's due to time-travel fallout from the Temporal Cold War, with Khan Noonien Singh now growing up in the 2010's-2020's rather than coming to power in 1992. Despite this, the Star Trek timeline has somehow largely remained unaltered, although this change in the timeline could be used to explain such things as the Cosmetically-Advanced Prequel nature of Discovery and Strange New Worlds as compared to the original series.
• Supernatural:
  • Justified in the season 2 episode "What Is and What Should Never Be", in which Dean experiences a life in which his mother was never killed and consequently he, Sam and John never became hunters. He and Sam have the same phones with the same numbers, but it's all a vivid hallucination caused by a Djinn, so it doesn't have to make total sense as long as Dean believes it.
  • In the Season 4 episode "In the Beginning", Castiel sends Dean back to 1973, where he meets his parents and maternal grandparents at a pivotal point in their lives. His presence has no effect on the way things play out, and as Castiel explains, it couldn't have; the reason he sent Dean back was so he could learn the truth about exactly what happened to Sam as a child and why.
  • In the Season 6 episode "My Heart Will Go On", an angel goes back in time and saves the Titanic from sinking. This resulted in thousands more people being alive today and many changes. However, the brothers are so central to the destiny of the world that new timeline arranges itself around them. They themselves are pretty much unchanged but the people near them have their lives altered in some ways big and small. Most likely this protection only applies to people closely connected to the brothers. The timeline appears to be trying to repair itself in that episode however, since the plot is kicked off when descendants of the people who should have died on the Titanic start dropping off like flies. This is the work of the angry Fate, who knows Castiel organized it all to get more souls for his side of an angelic civil war.
• Travelers has possibly the most resilient timeline in all of fiction. In the second episode they save 11,000 people and there is absolutely no effect to the timeline. Half way through first season they manage to prevent an asteroid impact that kills 91 million people and the change to the future is so subtle that operations continue for weeks without them realizing that anything was altered at all. That's ultimately subverted in season 3 by the discovery of an even more catastrophic event unwittingly caused by two of the people who are still alive because the previous one was prevented.
  • Season 3 in general introduces some larger scale consequences to changes in the timeline while still keeping some things the same, mostly significantly stopping the team ever travelling back in the first place. Among many other things, this means Marcy is the original Marcy and was never brain-damaged, yet she was still on the bus the day Traveler!Marcy met David (having not met David before in this new timeline).
• The Twilight Zone:
  • The Twilight Zone (1959): In "The Parallel", an astronaut returns to an alternate Earth where his family and superiors are identical, but he himself has a higher military rank and the President is different.
  • The Twilight Zone (1985): In "Memories", the history of the alternate universe is extremely similar to ours in spite of the fact that people have been able to remember their past lives for centuries, if not millennia. For instance, the interrogator asks Mary McNeal if she was one of the Borgias, Attila the Hun or Adolf Hitler in one of her past lives. He also mentions incidents of mass murder in Russia, Guyana (seemingly the Jonestown massacre) and Uganda. It is only in recent years that history has diverged in any significant way as the burden that everyone feels because of these memories is causing society to break down.
  • In The Twilight Zone (2002), a time traveler attempts to kill Adolf Hitler as an infant and succeeds. However, the nanny who discovers the scene panics and passes off a gypsy infant as him, changing nothing and creating a Stable Time Loop.
• One of the main plot points of Ultra Galaxy Fight: The Absolute Conspiracy being the result of Absolute Tartarus's meddling with the time stream to assemble his army to battle the Ultramen by conscripting parallel isotopes of those now deceased original villains.
  • To start, he goes back long before Belial's exile, and when he meets the fallen Ultra before his merger with Rayblood, followed by going back into Tregear witnessing Ultraman Hikari's transformation into Hunter Knight Tsurugi and his subsequent disillusion with the people of the Land of Light and like Belial, this was before he even merged with Grimdo. In both ways, Tartarus informs them of their future before he bargains them a place for The Kingdom. In Belial's case, he's made aware of his failures and his demise at the hands of his own son, laughing maniacally knowing everything he's fighting for would go All for Nothing.
  • And by undoing Reibatos's death and creating a parallel isotope version of the original, Tartarus commands Reibatos into reviving other deceased Ultraman villains, that even includes the Gua Army. The Ultra Brothers discover this during their battle with Mold and Juda before they see Belial and Tregear in their pre-corrupted forms emerging from Tartarus's portal.
• In the Warehouse 13 episode "Endless Terror" Paracelsus goes back in time 500 years and kills the Regents of Warehouse 8. In the present, history alters so that he's run the Warehouse singlehandedly ever since, and it's now a high-tech monolith to artifact analysis and exploitation. Valda, who in the original timeline was a Regent who made a Heroic Sacrifice, is now Paracelsus's heavy; Vanessa and Hugo reluctantly work in his human experimentation unit; and Abigail is the Wetware CPU of the Warehouse computer systems. Lampshaded by Claudia, who says the same people are drawn towards the Warehouse in any reality, prompting Pete to sarcastically wonder if MacPherson and Sykes run the break room. Artie also notes that the logos of past Warehouses show that they were associated with the same empires, indicating that Paracelsus doesn't seem to have altered history beyond the Warehouse itself.

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