Predestination paradoxes in television

A predestination paradox is a common literary device employed in many fictional and mythological works, dealing with various circumstances and paradoxes that can logically arise from time travel.

This page describes several examples of predestination paradox in literature. For more popular culture examples see Predestination paradoxes in popular culture, Predestination paradoxes in literature, Predestination paradoxes in film, Predestination paradoxes in video games, and Predestination paradoxes in comics, manga, and anime.

American Dad

• In the episode, "Fart-Break Hotel", at the hotel, Steve becomes interested in a portrait of a woman painted by Patrick Nagel in 1981. Wishing he could meet the woman in the painting, the concierge Héctor Elizondo suggests using the power of his mind to travel back in 1981 so Steve can meet her. After Steve does so and travels back in 1981, he meets Patrick Nagel, who soon drugs his champagne and knocks him out cold. Steve awakens on the bed [...] and sees the painting of the woman. When Nagel explains that he painted Steve, Steve realizes, much to his shock, that by traveling back in time, he himself becomes the woman painted in the portrait.

American Dragon: Jake Long

"Hero of the Hourglass"

• In the episode of American Dragon: Jake Long, "Hero of the Hourglass," Jake travels back to 1986 and encounters the past version of the Huntsman. Back then, the Huntsman had a goofy sounding voice. Later, Jake causes the past Huntsman to fall into the pit of a monster, which is apparently how the Huntsman got the voice of his present day counterpart.

Babylon 5

Babylon 4 and Babylon 5

• In Babylon 5, it is established that the titular station's predecessor, Babylon 4, vanished several years before. When it mysteriously reappears in the series' first season (taking place in 2258), it appears to have been dragged through time. The crew of Babylon 5 manage to evacuate those on Babylon 4 before it vanishes again ("Babylon Squared"). Two years later, led by letters left in the distant past by a Minbari prophet named Valen, the crew of Babylon 5 realized that it was they who "stole" Babylon 4 in the first place to serve as a base of operations for a war a thousand years in the past ("War Without End"). They then travel back in time to accomplish this before Babylon 4 can be destroyed by their enemies, trying to avoid their earlier selves when the station gets shunted to 2258. The former Babylon 5 commander, Jeffrey Sinclair, stays behind and takes Babylon 4 back to 1260, where it fulfils its place in Minbari history. Sinclair is also transformed during the journey into a Minbari, and introduces himself to those he meets in the past as Valen, eventually leaving the prophecies that will guide his future friends and self full circle. This is an example of a dual Predestination and Ontological paradox as the letters, combined with Jeffrey Sinclair's knowledge of Minbari history, culture and government, form a causal link (ontological) and one of the key characters in the plot, Delenn, is directly descended from Valen (predestination).

Londo Mollari and G'Kar

• Also in Babylon 5, Londo Mollari has a recurrent prophetic dream in which he kills, and is killed by G'Kar. He sparks a genocidal war by his own Centauri people against G'Kar's Narn, but in the long run, this leads to his own and his race's enslavement by the Drakh. After years, he captures John Sheridan and Delenn, and explains the situation to them. He sets them free, in return for their promise to liberate his people. But the only way this plan can succeed is to keep it from the Drakh, who have implanted him with a Keeper that can read his mind. He realizes that the only way to save his people is for G'Kar to strangle him; the violence awakens the Keeper, forcing him to fight back, and so the prophecy is fulfilled.

Beast Wars: Transformers

• The show Beast Wars: Transformers took place several generations down from the characters of the original Transformers show. Megatron, the leader of the story's villains (the Predacons) desired to travel back in time to prehistoric Earth and destroy the ancient Autobots as they hibernated, thus preventing them from winning the war that took place in the original show. However, as he and his minions crash-landed on Earth, they realized that the planet could not be the Earth they were familiar with because it had two moons. However, the second moon was revealed to be an alien planet killer which the characters destroyed - thus, they made Earth a single-moon planet by travelling back in time.
• Also, much later in the series, the Maximals discovered a small shuttle inside the ancient Autobot starship (The Ark) that there was no record of in the history files - because history was still being made at the moment, and they used the shuttle to travel back to their home planet and time.

In the show one of the Maximals inadvertently show prehistoric humans how to build weapons to defend themselves. The Maximal who showed them was himself a former predicon, a decedent of the Deception

Bionic Six

• In a Bionic Six episode, when Professor Sharp creates a time portal to send a team to prehistory to learn which power killed the dinosaurs, his brother, Scarab, sends henchmen to steal this power. In the end, nobody learns what killed the dinosaurs, but its hinted that they were killed by the radiation that came out from a gun the villains left in the past.

"Bubu Jing Xin"

In the Chinese television series Scarlet Heart and the book it was based on, the main character Ma'ertai Ruoxi travels back in time to the Qing Dynasty of China during Kangxi Emperor's reign and she creates the outcome of history by inadvertently starting the chain of events through her initial attempt of altering them, resulting in the Yongzheng Emperor's rise to power.

Danny Phantom

• The episode The Ultimate Enemy shows Dark Danny, an evil version of Danny Phantom ensuring his younger self turns into him by going back in time in disguise of his past self and making sure that everything its where it should be. Danny eventually returns and defeats Dark Dan but is too late to save his family. Luckily, Clockwork saves them.

Darkwing Duck

• In Darkwing Duck, the characters are called one day to a science lab where they have recently unearthed a large chunk of amber that appears to have Darkwing Duck preserved in it. The present-Darkwing and the other characters travel back in time to investigate. However, events lead to Darkwing falling in a pit of sap, and is thus preserved for eons. The episode ends with the other characters returning to the lab in the present to break Darkwing out of the amber.
• In another episode, Paraducks, Darkwing and his daughter Gosalyn accidentally travel back in time to find Darkwing as a youth. Darkwing is disappointed by seeing how geeky he was at Gosalyn's age, and also finds how close he came to joining a criminal gang when it breaks into a record store. Before he can stop the gang, Gosalyn warns him to avoid altering history; Darkwing retreats, and the two return to the present..except that St. Canard has been taken over by the very gang they encountered, with a snivelling no-longer Darkwing as a member of the same gang (an example of accidentally preventing the predestination paradox). Gosalyn and Darkwing find they have to go back in time and inspire the young duck to become the hero of the present.
• In a third episode, "Quack of Ages", Quackerjack travels 700 years back in time to stop the invention of the yo-yo by one of Herb (and possibly Binky) Muddlefoot's ancestors, and Darkwing and Launchpad follow him, arriving around 1 month after he did. Quackerjack used this time to work his way into King Herbeth's court as a new adviser(in what capacity is never revealed) and Darkwing's initial attempts to expose him end with DW being run over by the King's carriage. Later, upon Darkwing's arrival at Castle Canardia, Herbeth shows them his new invention, a yoyo consisting of an anvil with a rope wrapped around it, which falls on Quackerjack's left foot. Darkwing states that he likes it, though it needs a little work. Next, Herbeth produces an exploding version of unknown construction which predictably blows up in Quackerjack's face, leaving him with minor injuries, and prompting him to tell Herbeth to continue working on it. The third version is a normal yoyo with a gag boxing glove that comes out and punches Quackerjack's beak. Finally, Darkwing returns with Binketh, a peasant ancestor of the Muddlefoots who Quackerjack had kidnapped so he could have DW tried and executed as a warlock, and she reveals this fact, which results in Herbeth ordering Quackerjack's arrest. During the ensuing fight, he gets tangled in DW's grappling line and DW demonstrates how it should work. Therefore, by going back in time to prevent the invention of the yoyo, he helped cause it.

Dexter's Laboratory: Ego Trip

• Dexter is attacked by robots sent to destroy the "one who would save the future." After defeating the robots, he travels to the future to see how he will save it. In doing so he recruits copies of himself from other times to fight his nemesis. At the cruicial moment, his sister Dee Dee comes through the time machine and pushes the button to destroy the Evil Villain's fortress, thus saving the future. Angry, the various versions of Dexter build the very robots he meets at the beginning of the movie and send them back to destroy the one who will save the future.

Doctor Who

"Day of the Daleks"

• In the 1973 Doctor Who serial "Day of the Daleks," guerillas from the 22nd century travel back in time to prevent their own future from coming to pass. However, they discover that it is their actions that actually cause that future to happen. In that case, the loop is broken, not by them, but by the Doctor. As his existence is not dependent on the loop, he is not caught in the paradox and can act freely, his actions presumably causing that future to cease to exist.

"Mawdryn Undead"

• In the 1983 Doctor Who serial Mawdryn Undead, the Doctor encounters his old friend Brigadier Lethbridge-Stewart in 1983 recovering from a nervous breakdown, which is eventually revealed to have been by him travelling back to 1977 and meeting his 1977 self due to a phenomenum called the "Blinovitch Limitation effect".

"The Curse of Fenric"

• In the 1989 Doctor Who serial The Curse of Fenric, Fenric brings a Haemovores from a future where years of pollution has caused humans to mutate into Haemovores, and orders him to dump toxins into the sea, which would create a Predestination paradox, but he kills Fenric, and himself, averting it. In the same serial, Fenric causes Ace to save the life of her grandmother and her mother as an infant, creating her own future.

"The Parting of the Ways"

• In the 2005 Doctor Who episode "The Parting of the Ways", the Doctor's companion, Rose Tyler, absorbs the energy of the time vortex to save the Earth from the Daleks. She also uses the power to scatter the phrase "Bad Wolf" throughout history as clues, to lead her past self to the position where she will absorb the energy of the vortex to save the world.

"Blink"

• In the 2007 Doctor Who episode "Blink", the Doctor becomes stranded in 1969 and uses information gleaned from the future in order to communicate with a woman in 2007, Sally Sparrow. Through the Doctor's intervention from the past, knowledge and items come into Sally's possession that are used to defeat his enemies and return the time machine to him (sometimes without Sally realising). At the end of the episode Sally meets the Doctor by chance and, realising that she has encountered him at a point in his personal timeline before the events of the episode have taken place, gives him the information that he will later use to make contact with her past self.
• Also, when Sally and her friend Kathy are in the old house, a man comes to the door. This causes Sally to greet the man at the door and Kathy to be left alone, which sends Kathy back in time to 1920. Kathy lives out her life in the past and, just before her death, she forces her grandson to promise to hand-deliver a letter to Sally at the old house, which he does. This causes Sally to greet the man at the door and Kathy to be left alone, to be sent back to 1920.

"Time Crash"

• In the 2007 Children in Need special, "Time Crash", the Tenth Doctor suddenly comes up with a solution to a problem involving the collision of his TARDIS and that of the Fifth Doctor's. The Fifth Doctor then realises that he will remember the solution, having observed the Tenth Doctor performing it (who in turn remembered from when he was the Fifth Doctor).

"The Fires of Pompeii"

• In the 2008 Doctor Who episode "The Fires of Pompeii", The Doctor and Donna Noble land in the forum of Pompeii on the morning of August 23, 79 AD. Knowing that Mount Vesuvius is going erupt in under ten hours, Donna desperately tries to persuade the people of Pompeii to vacate the area, but the local Oracle, who is noted as predicting the future with 100% accuracy, tells them that she has foreseen no impending disaster. After learning that the Oracle has been turned into a Golem-like creature known as a Pyrovile, thus explaining the aptitude in seeing the future, the Doctor and Donna eventually go into Vesuvius' magma chamber, where the Pyrovile have installed a device that is slowly turning the human population above them into more Pyrovile. Realizing that the device will, among other things, prevent the eruption if allowed to remain operational, the Doctor destroys it, dooming Pompeii to its historical fate.

It is mentioned during the episode that some events in history are 'fixed' and some are 'in flux', meaning that there are some occasions where the Doctor cannot change history, Pompeii being cited as an example of a 'fixed' point.

"The Doctor's Daughter"

• In the 2008 Doctor Who episode "The Doctor's Daughter", the TARDIS forcibly brings the Doctor and his companions Donna Noble (Catherine Tate) and Martha Jones (Freema Agyeman) to the planet Messaline as it locks onto the DNA of his daughter, Jenny. However, it brings them there before she is created, and almost immediately after he lands the Doctor's hand is forced in a progenation machine, which uses his DNA to create an adult soldier within moments — the Doctor's daughter, Jenny.

"Silence in the Library/Forest of the Dead"

• In the 2008 two parter Silence in the Library and Forest of the Dead, The Doctor meets Professor River Song, a companion who had travelled with a future version of the Doctor and summoned him to help solve the mystery of the disappearance of 4,022 library visitors. However she later realises that she has summoned the wrong version, one which doesn't know her yet. She had been given the future Doctor's sonic screwdriver, which baffled the present day Doctor as to why he would do that. At the end of the second episode, Song & the Doctor realise that the only way to save the library's inhabitants is to create more memory in the Library's computer and the Doctor prepares to wire himself up as the memory, despite the fact that it would kill him. Song knocks him out and takes his place, as she realises that if The Doctor dies they would never have met, therefore sacrificing their time together. She dies but saves the 4,022 trapped people as well as Donna Noble and the Doctor (who will now meet up with Song later in his personal timeline). Just as he is about to leave, he realises that there was a reason he gave Song his Sonic Screwdriver. Opening it he finds a data ghost, which has saved Song's consciousness, and then manages to upload it onto the Library Computer, allowing her to live on inside the computer. His future self had known that River Song was going to die, therefore adding the data ghost to the screwdriver and allowing for her to be 'saved'.

In Doctor Who the fourth season, featuring The Tenth Doctor An Ood tells the doctor a prophecy, "It is returning through the darkness./ He will knock four times./ Your song is ending." All these prophecies came true: "It is returning" meaning Gallifrey, home planet of the Time Lords, "He will knock four times" referring to Someones knocking Event, "Your song is ending" meaning his death/regeneration, later "edited" to "This song is ending, but the story never ends" meaning he successfully regenerates.

"The Big Bang"

• In the episode The Pandorica Opens, the Doctor is imprisoned in a prison box called "the Pandorica" by an alliance of his enemies including Daleks, Cybermen, Sontarans, and Autons. In the concluding episode, The Big Bang, a future version of the Doctor travels back through time and tells the Auton duplicate of Rory Williams to open the Pandorica and free him. Rory does this, causing the Doctor to journey back at a later point in his own time stream and tell Rory to free him.
• While visiting a museum that houses the Pandorica, a young Amelia Pond's drink is taken from her by someone she does not see. After meeting the Doctor, the Auton duplicate of Rory, and her future self, Amelia complains that she is thirsty. To rectify this, the Doctor travels back through time and returns with the drink that was taken from Amelia previously. The Doctor taking Amelia's drink causes her to be thirsty which is what makes him travel back in time to take the drink in the first place.

"Let's Kill [...]"

• In the 2011 episode of Doctor Who "Let's Kill [...]", Mels, a friend who Amy and Rory name their daughter Melody after, turns out to be a pre-regeneration version of River Song, who in the prior episode, "A Good Man Goes To War", was established to be an alias used by their daughter as an adult, an alias she adopts shortly after regenerating and hearing the Doctor, Amy, and Rory refer to her as such, having known her only by her alias until recently.

Doctor Who Expanded Universe

"The Mutant Phase"

• In the 2000 audio drama "The Mutant Phase" the Daleks are mutating into creatures that threaten the Universe. To prevent this they try to draw the Fifth Doctor into the future so he can help them. This attempt causes him to materialise in 2158 during the Dalek occupation of Earth, where his presence causes a Dalek to be stung by a wasp which lays eggs inside. This causes the mutation to spread through the Dalek population. The Doctor then goes into the future and develops a way to treat the infection. The Dalek Emperor in the body of a Thal travels back with the Doctor to avert the Mutant Phase and tells the Daleks of the infection, as well as instructing them to use the cure. However the Doctor realises the Emperor giving the Daleks the cure caused the Mutant Phase, as the Daleks could have removed the eggs themselves, but the cure didn't work meaning that the mutation spread. The Doctor tells the Emperor this, causing the cure to be smashed and the Emperor to be erased from existence.

"The Time of the Daleks"

• In the 2002 audio drama "The Time of the Daleks" a Dalek fleet is trapped in the Time Vortex. 3 Daleks escape, but when the Pilot touches General Learman it is destroyed. Due to this General Learman is mutated into a Dalek to be a Pilot. The Daleks return to the Vortex but fail to free themselves, leading to Daleks including the Dalek Learman escaping the vortex. When Learman touches her past self she is destroyed, meaning Learman is mutated into the Dalek she destroys and the Daleks are trapped in a time loop.

Duck Dodgers

• In the episode "Quarterback Quack", Martian Commander X-2 (Marvin the Martian) goes back in time to prevent Duck Dodgers from winning a NCAA football championship game (which division is never revealed) back in college because the win was apparently crucial to Dodgers being chosen for the space program, and, by extension, his being frozen in a space shuttle for around 300 years. Finding out upon his arrival that Dodgers was just a water boy instead of the team's star quarterback, he poses as a history professor to get rid of the current quarterback by giving him a "project" (really sending him to observe Custer's Last Stand), and ensures that Dodgers would be chosen as his replacement. When Dodgers lost his confidence right before the final play of the game, X-2 slaps a "brainwave override receptor" on Dodgers' helmet, and helps him score a winning touchdown. Therefore, by going back in time to prevent Dodgers from winning the game, he actually causes it to occur, which the Martian Queen points out to him upon his return to the future.

El-Hazard

• In the anime series El-Hazard, the main character Makoto Mizuhara and three other people from Earth are sent by Ifurita to the world of El-Hazard. The actions of these characters while on El-Hazard lead to both the awakening of Ifurita (who had been in suspended animation for a millennium) and to her being sent into Earth's past, allowing her to be present to send the Earthlings to El-Hazard in the first place.

The Fairly OddParents

• In the episode "Odd, Odd West", Timmy's Dad takes Timmy's Squirrely Scout troop to Dimmsdale Flatts, a ghost town just outside of Dimmsdale. Upon their arrival, they find that local real estate mogul Doug Dimmadome, owner of the Dimmsdale Dimmadome, is moments away from demolishing the ghost town in order to build a "maxi-minimall" in its place. As a result of Dad's disapproval of this idea, it is revealed that the deed to Dimmsdale Flatts vanished without a trace about 120 years before the Scout troop's trip. After spending the night in a jail cell full of coyotes, Timmy wishes that he could go 120 years back in time. After he, Cosmo, and Wanda arrive in the past, they observe Chester, A.J., Sanjay, and Vicky's ancestors doing various things that apparently run in their respective families (e.g., A.J.'s ancestor is an inventor and Vicky's is an outlaw babysitter named Vicky the Kid). When the adults of the town give Vicky the Kid the deed in lieu of money, Timmy decides to do something about it. Before noticing Dimmadome's small army of bulldozers, Timmy had found a statue of the "Masked Stranger", who can best be described as himself dressed as The Lone Ranger. Donning this costume, Timmy challenges Vicky the Kid to a game of rock-paper-scissors, and wins. After taking the deed from her, and hiding it in "the one place where none of the illiterate boobs would ever think to look": the instruction manual to a computer that A.J.'s ancestor had built, the three time travelers return to the present, where Timmy presents the deed. Therefore, the deed disappeared because Timmy had hidden it.
• In another episode, "The Secret Origin of Denzel Crocker", it is revealed that Timmy's fairy-obsessed teacher, Mr. Crocker, is extra mean every year on March 15. After learning that March 15, 1972, was the "worst day of Crocker's life" while tracing his past, Timmy, Cosmo, and Wanda go back in time to March 14, 1972 to prevent whatever caused Crocker to become so bitter, mean, sadistic, and obsessed with fairies. Upon their arrival, they find a nice, helpful, and popular Crocker, who is going to be awarded on March 15 for his numerous good deeds. Wanda notes that there is something familiar about all of this, but is unable to "put (her) wand on it". When they follow Crocker to his home, they discover the reason: Cosmo and Wanda were his fairy godparents. (There is no explanation for why they were reassigned to Crocker, since in "Father Time", which takes place two years before the main past events of this episode, they were assigned to a certain Bill Gates. Also, there is no explanation for why 70s Cosmo and Wanda don't recognise Timmy.) At the ceremony the following day, Crocker is about to give his acceptance speech, when Wanda suddenly remembers that that is the moment Crocker's life crumbled. Timmy immediately tells her to cut the PA system's power, telling Cosmo to not do anything stupid. Timmy then tackled Crocker on stage before he had the chance to say anything while Wanda switched off the power. While Timmy explained himself to Crocker and 70s Cosmo, the future Cosmo inadvertently switched on the power, just as Timmy warns Crocker not to tell anyone he has fairy godparents, which is then broadcast across the town. Right on cue, the 1972 version of Jorgen von Strangle dropped onto the Town Hall's lawn and, with the help of a small army of MIB-type fairies, erased every good deed Crocker had performed using Cosmo and Wanda's magic from the town's memory, including his, ruining his life because the crowd now thought that they were there to punish him. Therefore, by going back in time to prevent Crocker's life from being ruined, Timmy turned out to be the person most directly responsible for Crocker's paranoid and insane persona in the present. It is also the stress of trying to remember fairies that causes Crocker's future appearance.
  • This episode also reveals the origin of Crocker's Fairy Tracker 3000: Timmy used A.J.'s Crocker Tacker 3000 to locate Crocker in the three time periods visited, and he left it in the past, only for Crocker to put a lock of 70s Cosmo's hair in it and write "FAIRY GODPARENTS EXIST" on it before '72 Jorgen erased his memories of Cosmo and Wanda.

Family Guy

• In the episode The Big Bang Theory, Brian and Stewie travel outside of the space-time continuum before the big bang happened. However, the explosion of Stewie's return pad causes the big bang, thus making Stewie create the universe and the universe created him and so on. But when Stewie's half-brother Bertram goes back in time to kill one of Stewie's ancestors Leonardo da Vinci, the universe starts to cease to exist. Stewie and Brian travel back in time and stop Bertram, but Leonardo da Vinci is dead. Stewie sends Brian back to the future and Stewie has frozen himself for nearly 500 years. Stewie states to Brian that he injected some of his DNA into Leonardo's girlfriend, thus causing another predestination paradox where Stewie is his own ancestor.

• Stewie and Brian travel back in time using Stewie's time machine. They are warped outside the space-time continuum, before the Big Bang. To return home, Stewie overloads the return pad and they are boosted back into the space-time continuum by an explosion. Stewie later studies the radiation footprints of the Big Bang and the explosion of his return pad. He discovers that they match, and he concludes that he is actually the creator of the universe. He explains his theory to Brian, who replies with "That doesn't make any sense; you were born into the universe. How could you create it?" Stewie explains that it is a temporal causality loop, which is an example of a predestination paradox.

The Flipside of Dominick Hide

• In The Flipside of Dominick Hide, Dominick Hide is a time traveller assigned to learn about 20th century transport systems. Learning that his great-great-grandfather lived in the time and place he is studying (London in 1980), he breaks the rules of his job in order to track down his relative. Though he does not find him, he does have an affair with a woman which leads to her giving birth to a son, Dominick's great-grandfather. Thus the great-great-grandfather Dominick was searching for was in fact himself. It is eventually revealed that Hide's superior knew about the loop and deliberately allowed Hide to break the rules in order to fulfill it.

Futurama

• Futurama explores the predestination paradox in its main story arc. The main character, Philip J. Fry was cryogenically frozen for a millennium in the year 1999, reawakening on December 31, 2999. In the episode "Roswell That Ends Well," Fry travels back in time. He is instructed by Professor Farnsworth not to do anything to change history, "like [...] your own grandfather." Fry tries to protect Enos from harm, though actually causes more near-damage to him. Fry is so determined to protect a reckless Enos (who he believes is his grandfather) from harm that he hides him in an abandoned building. The building turns out to be part of a nuclear weapon test, which kills Enos. Fry then has [...] with Enos' fiancée Mildred, believing that she cannot be his grandmother since he still exists. However, Farnsworth points out that in doing so, Fry has become his own grandfather. This causes him to have a unique brainwave pattern that makes him immune to the greatest threat of the universe, the evil Brainspawn. In a later episode, he is able to trap them in a singularity before they destroy the Universe, but accidentally traps himself with them as his transport system breaks down. He is shown the Nibblonians caused his freezing so he could stop the Brainspawn, which he is angry at. The Brainspawn and Fry work together to travel back in time and prevent Fry from ever being frozen, meaning that he could not trap the Brainspawn, as only he can travel back to that point. However, when he reaches the past, he realizes that to save humanity, and the love of his life, he has no choice but to make sure he does stop the Brainspawn. He pushes himself into the cryogenic freezer, but leaves a message to Nibbler, who was supposed to make him fall in, ensuring that he has safe transportation so that he escapes when the Brainspawn are trapped.
• In the episode "Roswell That Ends Well" it is also revealed that the UFO that landed in Roswell, New Mexico was actually the scattered pieces of Bender that the military scrapped together to make what looked like a mini UFO. Also the lifeform the military found and did an alien autopsy on was Dr. Zoidberg (Who survived due to having multiple organs such as four hearts). As the Planet Express crew venture back to their time they accidentally drop Bender's head in the deserts of New Mexico. Although not too worried the crew go back to the same place he fell and found his head buried in the same place in the year 3000.
• The Futurama movie "Futurama: Bender's Big Score" explores Predestination Paradox even further with a time-travel plot involving a secret time travel code that is sent back from the future by Bender wearing a tuxedo and placed on Phillip J. Fry's [...] moments after being frozen in 1999 that would be read by Nudist Alien Scammers and set in motion the events of the movie. The movie's subplot is Fry's continued attempts to have a relationship with Leela, but she has already begun one with a deep-voiced, bald fellow named Lars. As Fry returns to his time of the year 2000, he causes a time-paradox duplicate of himself when he goes back an hour to get a pizza. His earlier version meanwhile goes of to have a life in the 21st century while Fry is accidentally frozen when trying to get money from his frozen self, only to unfreeze and have the Time-Code Tattoo burned off of his body by Nibblers laser eye. The duplicate Fry, depressed by his failed attempts to win the heart of Leela, glance's at a picture of her with Lars. A smoke accident ignites in his apartment after a mind-controlled Bender is sent back from the Future by the scammer aliens to kill Fry and shoots at him. the explosion causes him to lose his hair and inhale so much smoke his voice grows unrecognizably deep. It is upon this accident that Fry discovers that he himself is Lars. So he races back to the cryogenics lab to freeze himself, and start his relationship with Leela as Lars, Lars-Fry is eventually killed by a cryogenically frozen Bender Time duplicate that was suffering from a paradox loop and 20th century alcohol that Fry placed inside of a Cryogenics Tube when unfrozen caused him to blow up [...] Lars-Fry, the last alien and the time-duplicate Bender in the process, at his funeral the Bender of then removes the Time-code tattoo from Lars-Frys butt and travels back in time to 1999 to place it on Frys' butt in the cryo-tube, thus allowing the events of the movie to happen.

Gargoyles

• The time travel device of the TV series Gargoyles, the Phoenix Gate, comes with a provision that it cannot be used to alter history. Multibillionaire antagonist David Xanatos manipulates events to bring the Phoenix Gate into his possession, which he uses to travel back in time. There, he instigates a sequence of events that leads to the delivery of a valuable gold coin to his possession as a younger man, which he had used to build his fortune. He also arranged to have the instructions to do what he had just done sent to himself a few weeks before.
• In another episode, Goliath finds himself accused of causing the disappearance of another Gargoyle during The Blitz. He uses the Phoenix Gate to travel back in time in order to stop the event from occurring, but eventually causes the disappearance when events force him to bring the Gargoyle back to the present with him.

Heroes

• A significant story arc in the second season has Hiro Nakamura travel to 1671 Japan, where he meets and befriends Takezo Kensei, but finds he is not the hero he grew up admiring, and so sets out to bring the tales of Takezo to fruition himself. By effectively becoming the man on whom much of his own ideology is based, he creates a causal loop.

• A minor temporal anomaly is introduced in the episode "Our Father", wherein Claire Bennet is sent back in time sixteen years and sees herself as a baby. Here she tells her father, Noah Bennett, that the baby is his "Claire Bear", a nickname he will subsequently use for the next sixteen years. Claire has heard the nickname all of her life from her father, who in turn heard it first from the (future) Claire, establishing a temporal information paradox.

Kim Possible

• In Kim Possible: A Sitch in Time, Duff Killigen, Monkey Fist and Dr. Drakken go back in time to try to stop Kim and Ron from forming "Team Possible". At preschool, using a "Re-Juvenator", the three villains infiltrate the school as children to crush Kim's spirit. A young Ron tries to intervene, only for the villains to turn on him – but this drives Kim to save the day for the first time. Which means that by travelling back in time they created the "Team Possible" they were trying to destroy.

Lost

• Desmond Hume is informed by Ms. Hawking that "course correction" will prevent him from changing the future when he travels back in time. However, Desmond is later told by Daniel Faraday, who is time travelling himself, that Desmond is "special" and the "exception to the rule," implying Desmond can change the future when no one else can. Daniel explains to the survivors of flight 815 that they cannot change the future or cause anything in the past to happen differently from how it was originally seen. Sawyer demonstrates this by knocking on the hatch door yelling for Desmond, but Desmond never arrives because the two never met in that time period. Shortly afterwards Daniel is able to make Desmond open the door, because the two were supposed to meet each other. Desmond has no recollection of a previous time travel-related meeting with Daniel a few years earlier, however, but Daniel's message for Desmond to find Daniel's mother changes the future by having Desmond remember this meeting three years later immediately after Daniel imparts this on Desmond's past self—in effect, Daniel changed Desmond's memory of the event.
• In Season 4 episode "Cabin Fever", Richard Alpert visits the hospital shortly after John Locke is born on 30 May 1956. Richard visits him 5 years later and shows him six items, one of which is a compass. Years later on the Island, after John Locke has crashed there and skips through time, Richard gives him a compass to give back to him the next time they meet. Locke skips through time again to 1954, returns the compass to Richard and to convince him he is from the future, tells Richard to visit the hospital in 2 years after he has been born on 30 May 1956. Therefore the reason Richard visits Locke as a child, is because the future version of Locke told him to.
• When the characters end up travelling back in time in season 5, they cause a number of events that end up in their time travel in the first place. Sayid Jarrah shoots a young Ben Linus in an attempt to prevent him from growing up and harming the characters as adults (the classic "[...] [...]" paradox), but Ben's life is saved by Kate Austen and James "Sawyer" Ford, who take Ben to the Others in hopes of having him healed. Richard Alpert warns this healing will result in Ben being "one of them," meaning the characters ended up being responsible for Ben being the way he was in the first place.
• Daniel Faraday is a strong proponent of the idea that "whatever happened, happened," or the Novikov self-consistency principle, that the events in the past cannot be changed because they always happened with the time travellers' presence. However, in a desperate attempt to save the life of Charlotte Lewis, who will end up dying in the future from time travel displacement, Daniel tells the young Charlotte to leave the island, in the process causing a conversation the adult Charlotte remembers and tells Daniel about 30 years later. Daniel believes humans can be used as "variables" with free will that can change the future. He enters the Others' camp and demands to know where the hydrogen bomb is that he told them to bury 20 years earlier, in hopes of detonating the bomb to prevent "the incident," a catastrophic event that sets off the chain of events that leads to the series beginning with Oceanic flight 815 crashing on the island; if Daniel prevents the incident, he prevents the "hatch" and its computer from being built, preventing Desmond Hume from accidentally failing to push the button, which prevents flight 815 from crashing and prevents Charlotte from being sent to the island as part of the freighter Kahana. However, his attempt is ended when he is fatally shot by Eloise Hawking, his own mother. As he dies, Daniel realizes his mother, who convinced him to go to the island in the first place, had known this event would happen and was powerless to stop it, and in his dying breath reveals to her his identity as her son.
• In the episode "He's Our You", several characters travel back into the 1970s. One of them, Sayid Jarrah, encounters the younger version of Benjamin Linus, the leader of the Others, and a man who has committed various acts such as betraying the Dharma Initiative and causing their complete [...] by the Others, the manipulation and deceit towards various people on the show and caused much strife to Sayid personally including recruiting him to become an assassin during his wife's funeral. When Sayid meets Ben's younger version he believes that it is his destiny to kill him and prevent all of the bad things he does from ever happening. However when he does this by shooting him, Ben is taken to the Others where they state that they could heal him in a mysterious temple but, "his innocence would be lost" and he would "always be one of them." By trying to prevent Ben from doing the things he did, Sayid actually caused him to become the evil manipulator that he is and caused all of the evil acts he committed.

Misfits

• The Misfits frequently encounter a man called Superhoodie, who helps them out of dangerous situations. Alisha Bailey later discovers he is a future version of their friend Simon Bellamy. He asks her not to reveal his identity to his present-day self. Alisha agrees and the two begin a relationship. Future Simon is killed while protecting Alisha. As a result, she becomes much more respectful toward present-day Simon and the two eventually become a couple. Alisha is killed by the vengeful spirit of a woman named Rachel, who the misfits accidentally killed. As she dies, Alisha tells Simon about his future self. He acquires a one-way time travel ability from a power dealer named Seth and goes back in time to save her, eventually becoming Superhoodie.

Mirror, Mirror

• Nicholas is given two choices - he can return to 1919 through the mirror without the ring (and, therefore, without him being able to prove his identity), or he can stay in 1995 with Jo. Love wins out and Nicholas chooses to stay in 1995. This latter decision is a grandfather paradox, which results in the mirror disappearing and the cycle broken and then closed. If he had chosen the former decision (returning to 1919 via the mirror), the cycle would be completed and thus repeat itself. In this case, this is a predestination paradox. In both cases, the mirror is an ontological paradox.

¡Mucha Lucha!

• On the show Mucha Lucha in the episode "Woulda Coulda Hasbeena", Senior Hasbeena goes back in time to stop a flash from blinding him in an important wrestling match, when the three main protagonists try to stop him due to dangerous possible outcomes he unleashes a disco ball move there by blinding himself in the past causing the future he knows to that day.

My Little Pony: Friendship Is Magic

• In the 2012 episode It's About Time the main protagonist Twilight Sparkle is briefly visited by her ragged-looking future self. The time traveler tries to warn her about something, but disappears without explaining what it is. Being worried about the not-complete warning, she desperately tries to prevent any possible catastrophe, in the process sustaining every blemish seen on her future self. In the end, it turns out that the cataclysm does not exist, and Twilight goes back in time in order to save herself from wasting time - which closes the time loop.

Mystery Science Theater 3000

• In the episode Hobgoblins, after seeing the awful movie, Tom Servo uses Mike's time machine to go back in the past and, as he explains, "kicks him right in the shin". He believes this will prevent the film's director Rick Sloane from making the movie. However, Crow is reading about lesser directors, and comes across an entry on Rick Sloane: "The inspiration for the movie Hobgoblins is like a stout red automaton kicking me in the shins." So this means that Servo accidentally inspired the film.

Penguins of Madagascar

• In The Penguins of Madagascar, the episode "It's About Time" sees Kowalski constructing a time machine called the "Chronotron". A future Kowalski tells Private to convince his present self not to complete it. After he decides to destroy the Chronotron, another Kowalski from the future tells Skipper to convince him to save the Chronotron. When the present Kowalski spots his future selves, a vortex appears. The present Kowalski activates the Chronotron and goes back in time to talk to Private. When Private points out that if Kowalski had not invented the Chronotron then he would not have gone back in the first place to tell himself not to make it, the future Kowalski then goes back in time to talk to Skipper. Rico then throws the Chronotron into the vortex, sealing it. While a baffled Kowalski tries rationalizing that such a simple thing defies all laws of the universe, Skipper simply states that Rico is a maverick who makes his own rules, and tells Kowalski to invent something that will not destroy the world.

Pinky and the Brain

• In the episode "Brain of the Future", Pinky and the Brain are told by their future selves that in the year two billion A.D., a world domination kit would be available. Leaving the future Pinky and the Brain behind, the past duo flies off in the time machine, the sight of which causes nuclear war in the future, causing cockroaches to become the dominant species. The two are captured after they crash, and later steal the kit. They find another time machine and fly off again, telling the past selves about the kit, which Pinky has left on the ship. Their tampering with time comes clear when all of Acme Labs is revealed to be filled with hundreds of Pinkys and Brains.

Pokémon

• In an episode of Pokémon, a young boy discovers a time portal in a cave that connects the present time to a time millions of years in the past. He enters the portal, befriends a turtle-like Pokémon, and then returns to the present. Years later, as a young man and archeologist, he discovers a fossil of an extinct Pokémon species. With help from the professor, he is able to bring it back to life. He notices that it is wearing a pendant that he gave his Pokémon friend, thus establishing that it is the same Pokémon be befriended in the past. At the end of the episode, the Pokémon (now fully grown) returns to the past. This begs the question, then, of where the original Pokémon fossil came from.

The Powerpuff Girls

• In an episode of The Powerpuff Girls, Professor Utonium reveals to the girls that he originally devoted his life to science because he had seen a vision of some kind when he was a child. This drove him towards finding just what the vision was, by committing to science. The girls' nemesis, Mojo Jojo, learns of this and decides to travel back in time to prevent the creation of his enemies. However, the girls follow him into the past. Eventually, the child Utonium is knocked out and comes to as the girls are hovering over him - the aforementioned vision brought about by Mojo Jojo. In a similar episode Mojo Jojo tries to prevent the Powerpuff girls from being created-only to find that he (Mojo) started the train of events which resulted in the Powerpuff girls being created.

Primeval

• In one episode of the ITV series Primeval, the Team, along with some soldiers, go back to the Permian Era. While there they find the skeletal remains of a human being, as well as an abandoned camp, full of tents. In the last episode of the series, they go back to the Permian Era, and set up a camp. However, they are followed by two vicious Future Predator parents, and their young. While they are there, one of the soldiers, Captain Tom Ryan, is killed, by a Future Predator; the dying soldier realises and asks Cutter whether the skeleton was him, and he replies yes.

• In the third season of Primeval, it is revealed that the Future Predators are not natural creatures, and that they were, in fact, cloned by the ARC from the DNA of their future selves, which in turn existed because the ARC cloned them. When Helen Cutter figured this out, she decided that she must wipe out humanity to stop the ARC's work from causing Future Predators to exist, and, in turn, destroying the world. In Episode 3.3, Helen blows up the ARC with a bomb, and shoots and kills her estranged husband, Nick Cutter. When that attempt fails, she decides that she must go back in time to the root of humanity (the Pliocene) and kill off all of the Australopithecus, so that humans will fail to exist. She succeeds in [...] one family of australopithicenes, which turned out to be the First Family, and, in the series, Helen Cutter was actually responsible for their death, creating yet another predestination paradox. She tries to kill more hominids, but she is killed by a Troodon that followed her into the Pliocene from the Cretaceous, pushing her off of a cliff, where both Helen and the dinosaur died.

Red Dwarf

"Future Echoes"

• In the Red Dwarf episode "Future Echoes," there are several predestination paradoxes caused by images of the future appearing in the present. The first echo occurs when Lister is shaving, and his reflection shows him [...] himself. This distracts him, causing him to cut himself. Later, Lister has a nonsensical conversation with Rimmer, unaware he is talking to a future echo. When the real Rimmer enters the room, Lister's attempts to work out what's happening lead to Rimmer making the same responses heard in the echo. Lister later sees a future echo of the Cat with a broken tooth, and decides that if he can prevent this happening, he can prevent other events seen in the echoes. Realizing the Cat is trying to eat a robot goldfish, Lister tackles him to the floor before he can bite, breaking the Cat's tooth in the process.

"Stasis Leak"

• In the Red Dwarf episode "Stasis Leak," Lister reads in an entry in Rimmer's diary where it is written that Rimmer has seen his future self, who told him about a stasis leak and advised him to go into stasis to survive. At the time, Rimmer dismissed it as a hallucination. Later in the episode, Rimmer, Lister and Cat find the stasis leak and go back in time, where Rimmer tells his past self to go into stasis to avoid being killed. The past Rimmer dismisses it as a hallucination (brought on by eating fungus), although he writes in his diary, completing an unbreakable loop.

"Ouroboros"

• In the Red Dwarf episode "Ouroboros," Lister encounters an alternate reality where Kochanski survived instead of him. After adding his contribution to an in-vitro tube, he finds a supplies case labeled "ouroboros" (which was also written on the cardboard box he was abandoned in). He then realizes that he is his own father, and when the child is 9 months old, he goes back in time and places the child where he was left.

"Cassandra"

• The eponymous clairvoyant computer in the Red Dwarf episode "Cassandra" lies about what she has seen in an attempt to get revenge on Lister, since he will kill her. Her subterfuge leads directly to Lister inadvertently [...] her, after declaring his intention not to. Cassandra's genuine predictions include the concise predestination paradox "You die in about four seconds' time of a heart attack, after hearing the news that you're going to die of a heart attack."

"Timeslides"

• In the Red Dwarf episode "Timeslides", Dave Lister travels back in time using a mutated photograph of a pub in Liverpool where his band once played a gig to give his teenage self the idea of inventing the Tension Sheet (a stress relief tool invented by Fred 'Thickie' Holden, a former classmate of Arnold Rimmer, which earned him millions). This causes him to become rich and famous in the past and never get stuck on Red Dwarf. Arnold Rimmer, in an attempt to experience fame and fortune for himself, travels back even further in time to his school days, to give his own younger self the idea of inventing the Tension Sheet instead. Unfortunately for Rimmer, while he is giving young Rimmer the idea, the conversation is overheard by Thickie Holden (who sleeps in the next bed) and he is able to patent the idea before young Rimmer can, therefore putting everything back to how it was at the start of the episode.

Quantum Leap

• In the episode "Future Boy", time traveler Sam Beckett tells Captain Galaxy his theory of time travel. Captain Galaxy later reports the theory to a young Sam Beckett.

The Red Green Show

• In one of Ranger Gord's self-made nature cartoons on The Red Green Show, Gord used a predestination paradox to attempt to prevent a forest fire. He explained that in the future he would be working on a time machine, and would bring it to the present to pick himself up and travel to the past. Inexplicably, this happens, and Future-Gord and Present-Gord travel to the past to meet Past-Gord. The three manage to stop the supposed cause of the forest fire, but when they all travel to the future to celebrate, the time-warp creates a spark that sets the forest on fire.

SpongeBob SquarePants

SB-129

• Squidward accidentally transports himself to the future after SpongeBob and Patrick jellyfishing endeavors drive him to the Krusty Krab, where he locks himself in the freezer. 2,000 years later, he uses the time machine to go to prehistoric times. The prehistoric ancestors of SpongeBob and Patrick annoy him too, so he teaches them about jellyfishing, to make them leave. When he returns to the present, SpongeBob and Parick ask him if he wants to go jellyfishing. He then asks who invented the game. SpongeBob and Patrick tell him that he did. He then says "I'm going back."

Back to the Past

• SpongeBob, Patrick, Mermaid Man and Barnacle Boy transported to the time when young Mermaid Man and Barnacle Boy trap Man Ray in tartar sauce. But Patrick eat the tartar sauce and return to his time with SpongeBob. When they return, Bikini Bottom turn into Man-Ray-Opolis. They rescue past Mermaid Man and Barnacle Boy then return to the past to stop Patrick from eating tartar sauce. They failed, but more time machine come with another SpongeBob, Patrick, Mermaid Man, Barnacle Boy and even Man Ray. Man Ray confused and arrested.

Star Trek

"Tomorrow is Yesterday"

• In the Star Trek episode "Tomorrow is Yesterday", the Enterprise is accidentally sent back in time to 1967 to Earth. The ship is disabled and is seen as a UFO by the United States Air Force which sends a fighter plane to investigate. Captain Kirk orders a tractor beam activated to prevent the pilot from firing a missile at the Enterprise. However the plane is too fragile and begins to disintegrate. Kirk is forced to beam the pilot aboard the Enterprise. Immediately the pilot Captain John Christopher learns too much about Earth's future and returning him to 1967 becomes a risk to the timeline. Commander Spock eventually deduces that Captain Christopher must be returned to insure the timeline when he discovers that Christopher will father a son Sean Jeffery Christopher who will head an important Saturn space voyage that is critical to the timeline. However Christopher and the Air Force have film and audio from the recon flight that must be recovered to correct the timeline. Kirk and Lt. Sulu beam down to the Air Force base to retrieve the information. However their appearance trips an alarm, alerting the base police who go to investigate. Upon their arrival in a photo lab, Kirk is able to distract the police by brawling with them while Sulu escapes from a back room by beaming out. Kirk however is stranded with only his belt and phaser. Christopher convinces Spock that he is the only one who can find the room where Kirk is and Spock, Christopher and Sulu go back to Earth to rescue Kirk. Christopher however takes one of the policeman's guns after all have been disabled in an attempt to not go back to the Enterprise. Spock however anticipates Christopher's move and gives him a Vulcan neck pinch which disables him and all return to the Enterprise with all restored. Lt. Commander Montgomery Scott, the ship's engineer, by that time has figured out a way to get both Christopher back by traveling back in time to the Enterprise's arrival and beaming Christopher back into his fighter jet while the Enterprise is invisible to the tracking devices of the time. This is successfully done and then Scott uses the reverse principle of their earlier accidental time travel to return to their own time, thus completing the circle.

"Assignment: Earth"

• In the Star Trek episode "Assignment: Earth," the Enterprise travels back to 1968 to observe an especially turbulent era in history. They intercept a powerful transporter beam that carries a seemingly human male named Gary Seven and a cat. The two escape to Earth, where their mission is to prevent the launch of an orbital nuclear weapons platform. Seven begins to sabotage the rocket but is beamed away before he can finish. After several attempts to stop him, Captain Kirk and Spock confront Seven in his office. Unable to stop the malfunctioning rocket, Kirk decides to trust Seven, allowing him to use his computer to detonate the warheads before they start a world war. Afterwards, Kirk reveals the incident resulted in exactly the outcome shown in their historical records.

"Relativity"

• In the Star Trek: Voyager episode "Relativity," Captain Braxton of the future timeship USS Relativity recruits Seven of Nine to prevent the USS Voyager from being blown up by a temporal intruder. Her first two attempts are unsuccessful, and she ends up recruiting Captain Kathryn Janeway to find the intruder who planted the bomb. The intruder turns out to be a future version of Braxton, seeking revenge against Janeway, whom he blames for interfering with the timeline on numerous occasions and causing him to endure a 30-year exile on 20th century Earth (as seen in the episode "Future's End"). Relativity's First Officer, Lieutenant Ducane, arrests the present-day Braxton for "crimes he will commit," and promises Janeway that he will clean up the timeline. How this is to be done, however, or whether the events of the episode will continue to exist if he does so, is never explained. Here, the paradox was called the Pogo paradox (after the phrase "We have met the enemy and he is us" from the Pogo comic strip).

"Captain's Holiday"

• In the Star Trek: The Next Generation episode "Captain's Holiday," Jean-Luc Picard is contacted by two Vorgons from 300 years in the future. They claim that he is destined to find a powerful weapon that was stolen and hidden in the past, the Tox Uthat. Compelled by this prophecy, Picard finds it, but on discovering that the Vorgons were the ones who stole it in the first place, chooses to destroy it instead. The Vorgons then admit that this was what history had actually recorded and their attempts to change it for their own gain failed.

"Time's Arrow"

• In the Star Trek: The Next Generation episode "Time's Arrow," the USS Enterprise-D is recalled to Earth because Data's severed head has been discovered in an abandoned mine shaft underneath San Francisco from 500 years in the past. While investigating possible causes, Data is sent back to 19th century San Francisco, and after a battle with aliens who are sucking brain energy from humans, his head is severed and the mine shaft collapses. Data's body, which had returned to the future, was reconnected to the 500 year-old head, which, after some maintenance, was able to function normally.

"Trials and Tribble-ations"

• In the Star Trek: Deep Space Nine episode "Trials and Tribble-ations," the USS Defiant is sent back through time to the 23rd century, where they become embroiled in a plot to kill Captain James T. Kirk. In so doing, they end up effectively participating in the original series episode "The Trouble With Tribbles." (the slow continuous stream of tribbles that continuously "fall" out of the containment bin during Kirk interaction with the people below, is shown to be Capt Sisko and Lt. Dax testing and rejecting the tribbles still inside) A humorous reference is made to the predestination paradox when Julian Bashir suggests that he is meant to have [...] with a Lieutenant Watley (who he thinks is one of his ancestors) so that he can become his own great-grandfather, lest he cease to exist.

Star Trek IV: The Voyage Home

• In the 1986 film Star Trek IV: The Voyage Home, panels of ultra-thick acrylic glass were needed to construct water tanks within their ship's cargo bay for containing two humpback whales and tons of water. However, the Enterprise crew, without money appropriate to the period, found it necessary to barter for the required materials. Chief Engineer Montgomery Scott exchanges the chemical formula for transparent aluminum for several sheets of the material from a manufacturer called Plexicorp. When Dr. Leonard McCoy informs Scott that giving Dr. Nichols the formula is altering the future, the engineer responds, "Why? How do we know he didn't invent the thing?" (In the novelization of the film, Scott is aware that Dr. Marcus "Mark" Nichols (Alex Henteloff), the Plexicorp scientist with whom he and McCoy deal, was its "inventor," and concludes that his giving of the formula is a predestination paradox/bootstrap paradox.) The substance is described as being as transparent as glass while possessing the strength and density of high-grade aluminum. It was also mentioned in Star Trek: The Next Generation episode "In Theory."

Star Trek: First Contact

• In the movie Star Trek: First Contact, a Borg ship travels to April 4, 2063 from the 24th century to prevent humans from making contact with aliens. The USS Enterprise-E follows the Borg into the past and destroys the ship. However, debris and some Borg survivors land in the Arctic, where they go into suspended animation. Accidentally revived several decades later in the Star Trek: Enterprise episode "Regeneration," these Borg escape Earth and send a message to the Collective of that period, then still deep within the Delta Quadrant. It is implied that this signal—which would not be received until the 24th century—may be why the Borg decided to invade the Alpha Quadrant 200 years later.
• During the film proper, part of the Enterprise's crew reveal themselves to warp drive creator Zefram Cochrane and assist him in not only building, but launching the Phoenix, mankind's first warp ship. The event was referred to in an episode of Star Trek: Voyager by a member of the timeship USS Relativity, by saying that they are unable to correct this event (by removing the Enterprise's presence in that era) as it would negate their own existence.

Stargate SG-1

"1969"

• In the Stargate SG-1 episode "1969," a wormhole transports the SG-1 team to 1969, where they are arrested as Communist spies. One of their guards, Lieutenant George Hammond, who will be their commanding officer in the future, finds a note in Samantha Carter's equipment. The note, in Hammond's own handwriting, states, "George, help them." Because of this, the younger Hammond helps SG-1 escape. In his relative future, General Hammond will remember the incident and write the note, giving it to Carter just prior to SG-1 leaving through the wormhole, thus closing the loop.

"Prophecy"

• In the Stargate SG-1 episode "Prophecy," Jonas Quinn begins seeing visions of the future. One of these visions consists of an injured Major Carter being rushed to the infirmary. Jonas convinces General Hammond to pull Carter from the upcoming mission. Later, while working on the Stargate, and while the rest of SG-1 is still offworld, a power spike injures Carter in the same manner as in Jonas's vision.

"It's Good to Be King"

• In the Stargate SG-1 episode "It's Good to Be King", Harry Maybourne discovers a stele which describes future events and uses the knowledge to become the local ruler. The events described come to pass as the SG-1 team unwittingly fulfills the prophecy while attempting to circumvent it.

A Step into the Past

• In the Hong Kong TV series A Step into the Past and the book it was based on, the main character Hong Siu Lung travels back in time to the Warring States period of China and accidentally changes a few events. He thinks he has altered history, but in the end, he creates history by helping the tyrannical Qin Shi Huang rise to power.

Supernatural

In the season 4 episode "In the Beginning", Dean Winchester travels back in time to change the future but sets up the events leading to his parent's deaths and Sam's corruption by Azazel. However, Castiel, who sent him back in the first place, explains that regardless of his actions the result would have been the same.

Torchwood

"The Ghost Machine"

• In the episode "Ghost Machine," Gwen uses the "Ghost Machine", which gives her a vision of herself in the future holding a bloody knife and saying "Owen wanted to kill him." When the scenario arrived in real life, Owen was threatening a man with a knife. Having seen and heard what her 'future' self said, Gwen takes the knife from Owen, resulting in the old man taking advantage of the way she is holding the knife to commit [...]. The predestination in this case was a misinterpretation of the actual vision.

The Transformers

• In The Transformers episode "The Key to Vector Sigma", Optimus Prime assists in the creation of the Aerialbots who, in the later episode "War Dawn", are sent back through time, thus activating their vital role, and ensuring Optimus Prime's existence into the future.

The Twilight Zone

"No Time Like the Past"

• In The Twilight Zone episode "No Time Like the Past," the main character uses a time machine to go back in time to alter past events. After failing to warn a Hiroshima police captain about the impending nuclear attack, assassinate Adolf [...], and change the course of the Lusitania to avoid being torpedoed, he accepts that the past cannot be changed. He then uses the time machine to return to the town of Homeville in the year 1881. After reading in a history book that Homeville's schoolhouse will burn down because of a kerosene lantern thrown from a runaway wagon, he spots the wagon and attempts to prevent the fire, but instead causes the fire he intended to prevent.

"Cradle of Darkness"

• In an episode of The Twilight Zone entitled "Cradle of Darkness" (2002), a woman named Andrea Collins (Katherine Heigl) travels back in time in order to kill Adolf [...] as a baby. In order to do that, she commits [...], jumping from a bridge holding the baby. However, a maid from the [...] household sees the whole thing and replaces the child with a Gypsy baby who grows up to be Adolf [...]. But for Andrea's actions, this would not have happened, and she created the future she was trying to destroy.

Warehouse 13

"Where and When"

• In this episode, H.G. Wells (Agent Wells) reveals her "time machine", a machine that transfers one's consciousness into another person in the past and takes over their body. During this period, the person in the present is unconscious and after the experience, the person in the past remembers nothing (blacking out for the period of transfer, which is 22 hours and 18 minutes).
• In the earlier episode "Burnout", a former Warehouse agent named Rebecca St. Clair was encountered when the body of her former partner and romantic interest Jack is recovered. In "Where and When", it is revealed that their relationship began when they kissed. This kiss was prompted by Rebecca in 1961 while inhabited by her future consciousness from 2010, shortly before she dies. Thus, her older self began the relationship that she remembers.
• Pete and Myka only decide to travel to the past when H.G. Wells realizes that St. Clair was temporarily replaced by another consciousness because she blacked out for 22 hours and 18 minutes in the past; they also see a recording of themselves saying they should travel back in time; thus, they only go back in time because they have already gone back in time.
• Agent Wells' daughter was killed in the past, while she was not there, but the housekeeper blacked out, while there were reports that the housekeeper fought in Wells' style. She thus realized that she had to create a time machine to go back into the past, because it had already happened. Unfortunately, she, like Pete and Myka, could not change past events (instead simply becoming involved)

Xiaolin Showdown

Days Past

• The Xiaolin Warriors require a time machine in order to travel into the past in order to get help from Master Dashi in order to defeat a resurrected Wuya in the present, it is revealed that their enemy Jack Spicer has managed to invent a time machine that they could possibly use, only when he activates it a Jack Spicer from the future steps right through it saying hello to them before the present Jack Spicer walks through it himself while the Future Jack Spicer says that the time machine can only travel an individual backwards in time by only 10 seconds, leading to the creation of a causality loop of Jack Spicer traveling back in time by 10 seconds to say hello while his past self from 10 seconds ago walks through the portal to 10 seconds ago and say hello in the first place.