There are three versions of time travel most often used in science fiction—fixed timeline, dynamic timeline, and multi-verse timeline. This work looks at two works of science fiction and how they integrate fixed and dynamic timelines in their time travel narratives. In a fixed timeline, the future is fixed and therefore cannot be changed by someone going back in time, the opposite of which is the dynamic timeline, in which one can go back and change the future. The two works this paper will focus on are the 2012 Gravity Falls episode titled “The Time Traveler’s Pig,” and the 1961 The Twilight Zone episode titled “Back There.” Upon a first viewing of both episodes, it is easy to assume that they each utilize a singular version of time travel, mainly that “The Time Traveler’s Pig” is solely rooted in a dynamic timeline, whereas “Back There” works within a fixed timeline; however, these episodes present important interventions upon these types of time travel by interweaving both fixed and dynamic timelines into their narratives. Although there are some similarities between the two, there are much more differences in the degree to which they center their characters’ developments amidst the science fiction elements. In both episodes, the fixed-dynamic hybridization brings an added element of suspense by making us wonder whether or not these characters can indeed change the future; still, there are many disparities between the two. “Back There” fails to provide a satisfactory time travel story because in its attempts at centering a specific viewpoint on time travel, it succumbs to plot holes and does not allow for any meaningful character development to occur as a result of the time travel. “The Time Traveler’s Pig,” however, provides a compelling approach to time travel by centering the narrative around its characters’ relationships and the ways their use of time travel correlates with the outcome of these relationships.

The hybridization of fixed and dynamic timelines means these episodes use both types of time travel, and they both use the fixed timeline to preserve an overarching future; yet, while one episode has its characters cause this inevitable future, the other makes sure its character has nothing to do with it. In “Back There,” the fixed timeline presents itself through the major historical plot point of Abraham Lincoln’s assassination. When Pete Corrigan goes back in time, he goes to the exact place and day that the assassination is supposed to take place. This is the piece of the future he feels himself tasked to change; however, no matter what he does or does not do, he is ultimately unable to cause or change it. In “The Time Traveler’s Pig,” there is an overarching fixed timeline occurring which we know because of Blendin Blandin, the time traveler. The reason he travels to Gravity Falls is “to stop a series of time anomalies that are supposed to happen at this very location,” thus further cementing the addition of the fixed timeline by the end of the episode when the main characters Dipper and Mabel do indeed cause these time anomalies not in spite of but because of Blendin Blandin (“The Time Traveler’s Pig” 00:07:54-00:07:57). Here, the existence of the fixed timeline is determined by the actions of the main characters, thus giving meaning to the episode’s use of the timeline.

The character’s belief or disbelief in the power of time travel is an important one that both episodes address. In “The Time Traveler’s Pig,” it is clear that the twins Dipper and Mabel believe in time travel and that they can change the future. After finding out about time travel and getting their hands on the time machine, Dipper says, “Here it is, Mabel. Our ticket to any moment in history,” and then proceeds to devise a plan in which he will effectively change the future (“The Time Traveler’s Pig” 00:08:43-00:08:46). In “Back There,” the main character Pete Corrigan does not believe that if time travel were true, a person would be able to change the future. He believes in a fixed timeline version of time travel: “That’s a fixed date. It exists as an event in the history of our times. It can’t be altered” (“Back There” 00:01:89-00:01:93). The disparities between these two instances in which one character believes in their ability to change the course of time and another doesn’t present themselves in various forms throughout each episode. “The Time Traveler’s Pig” gives Dipper and Mabel time to ponder over how to best utilize time travel before they actually do it, whereas “Back There” does not give Pete so much as a heads up.

Choice is a tricky thing to navigate in a time travel narrative, but both episodes make it explicitly known just how much choice these characters are given. In both cases there is a problem that they feel the need to resolve. As mentioned earlier, Mabel and (primarily) Dipper choose to go back in time. The problem is that when trying to win a prize for his crush Wendy at a baseball throwing booth, Dipper accidentally ends up hitting Wendy in the eye with the ball, which then leads her into Robby’s (another guy who also likes Wendy) arms as he uses the opportunity of her being hurt to comfort her and ask her out. She accepts his offer, making Dipper shocked and upset and prompting him to ask Mabel, “Do you ever wish you could go back in time and undo just one mistake” (“The Time Traveler’s Pig” 00:06:11-00:06:14)? He chooses to go back a few hours before he hit Wendy so he could effectively make it so he doesn’t hurt her but wins the prize for her instead. Dipper not only chooses to go back in time, but he goes to a time that is personal to him. “Back There,” however, does the opposite of this.

In “Back There,” Pete does not choose to go back in time, but rather unknowingly ends up in 1865 after walking out of the club in which he was having the debate about time travel; furthermore, he ends up in a time that has no personal significance to him, but is rather a famous moment in history—the day of Abraham Lincoln’s assassination. Even though Pete begins the episode by not believing that someone can change the future when traveling to the past, when he does eventually get transported back he ends up trying to change its outcome because he is filled with the hope that he can do something. However, the plot works to actively prove Pete’s initial theory so much so that it even falls into a plot hole in order to maintain his belief. Pete goes to the police to warn them of Lincoln’s impending assassination because he rightly believes that when it comes to the president, law enforcement will pull out every stop to keep him safe; still, they cast him off as crazy and put him in jail. Even if they think he’s crazy, they would at least have to try and consider his claim since it involves the president’s safety. We end up finding out that one of the policemen did in fact believe him and warned people, which, coming from him, should’ve at least garnered the president some extra protection as a result. The plot jumps through many hoops to ensure the historical future remains unchanged, and does not allow Pete to cause it to occur, much less to stop it.

When regarding choices in these time travel narratives, another important aspect becomes how much small changes these characters are able to cause, thus bringing in the dynamic timeline portions of these episodes. In “Back There,” although Pete is unable to prevent Lincoln’s assassination, he does end up altering someone else’s future. In the beginning of the episode, he comes across William the butler when William accidentally pours coffee over him, and Pete is very nice about the entire thing and they part on good terms. When Pete gets back from the past, he sees the same William, who is not the butler anymore but rather sitting with the rest of Pete’s friends whilst dressed in expensive clothing. It turns out that William inherited his riches from his great-grandfather, who turns out to have been the only police officer who believed Pete’s warnings. William explains “He went all over town trying to warn people that something might happen. How he figured it out, nobody seems to know,” and even though people didn’t heed his warning, he did end up receiving much more opportunities because of this, thus leading to his amassing so much wealth (“Back There” 00:21:91-00:21:95). The one thing Pete does try to actively change, he is unable to, but he unknowingly ends up causing a smaller change by altering William’s future. The creator and narrator of the show, Rod Serling, states in his closing remarks, that this episode proves “on one hand, that the treads of history are woven tightly and the skein of events cannot be undone; but, on the other hand, there are small fragments of tapestry that can be altered” (“Back There” 00:23:83-00:23:94). This is a version of a hybrid fixed/dynamic timeline, which seems to want to placate its audience; however, the ending of the episode does not allow for a satisfying resolution. Even William, who Pete knows personally and whose life Pete is able to change, ends up an old-money “sophisticate” who preaches the superiority of inheriting one’s wealth as opposed to earning it. Pete appears visibly unwell by the end of the episode, so much so that his peers end up commenting on how distraught he looks. “Back There” centers its narrative around the time travel itself and in proving/disproving the character’s beliefs about time travel. This is not a bad approach, but the plot does not seem to care about developing Pete’s character in any way, and because his choices in the past do not stem from his motivations as a developed character, the time travel itself seems almost pointless. The time travel does not support the main character’s journey, but rather expects him to support it. In direct juxtaposition to this, “The Time Traveler’s Pig” uses time travel to both test and strengthen its characters and their bonds to each other.

In “The Time Traveler’s Pig,” meanwhile, the choices Dipper makes involving the time travel correlates with his relationships—he decides to go back in time to create a future in which he does not tarnish his chance with Wendy. This world gives Dipper multiple chances to change the future as well, which he is forced to do because he keeps repeating the same outcome after every try. It is here we actively see the fixed and dynamic timelines battling it out as Dipper keeps creating the same outcome albeit arriving at each in slightly different ways (such as changing up his throwing style and the dialogue being a bit different each time). He even voices his concern over this being a fixed timeline: “Is it possible that the forces of time naturally conspire to undo any new outcomes? No, no, I just need to try again” (“The Time Traveler’s Pig” 00:11:10-00:11:16). The moment in which the story shifts to a dynamic timeline is when Dipper decides to actively change a bigger variable in the story regarding his relationships. The time Dipper hits Wendy is around the same time his twin sister Mabel gets Waddles, the 15-pound pig she wins at the fair by guessing his weight after the carny accidentally gives it away. Although we don’t know this yet, the future that guarantees Dipper hitting Wendy is the same one that guarantees Mabel winning Waddles. Thus, when Dipper recruits Mabel into helping him in his newest attempt, he ends up changing the future and not hitting Wendy, whilst also causing Mabel to lose Waddles. The timeline shifts to a dynamic one as we see a complete shift in Dipper and Mabel’s relationship. We see that the negativity he wanted to change in his future is directly correlated to the positivity in Mabel’s future. Thanks to the time travel machine, Dipper is able to go into the future and see just how badly his choices hurt Mabel. When Dipper does eventually fix the timeline, he’s reverting it to its original outcome. Although the future ends up unchanged from that of the beginning of the episode, this lack of change is due to the character’s choice in keeping it the same in order to ensure his sister’s happiness. The time travel becomes a plot device that helps further challenge and develop Dipper’s personality by showing him to think of others, to prioritize his sister’s happiness. The decision of whether Dipper’s attempts at time travel will result in a fixed or dynamic timeline is eventually made by Dipper himself, whose active choices lead to the same fated outcome because he prefers it to the one he was able to change. “The Time Traveler’s Pig” effectively combines both fixed and dynamic timelines in a thought-provoking way by centering its characters’ relationships over the need to bolster a specific truth about time travel.

Both the Gravity Falls episode “The Time Traveler’s Pig” and The Twilight Zone episode “Back There” delve into a version of time travel that combines fixed and dynamic timelines, albeit to varying degrees of success. In the former, Dipper and Mabel are able to cause small changes whilst still creating the time anomalies Blendin Blandin had been sent there to prevent. In the latter, Pete Corrigan is unable to prevent Abraham Lincoln’s assassination whilst unknowingly giving one police officer a future of prosperity out of which the former butler William will emerge a rich sophisticate. Yet, “The Time Traveler’s Pig” effectively uses time travel to focus on its characters’ development through the choices they make, whereas “Back There” prioritizes the spectacle of time travel itself and neglects to offer a convincing character arc for Pete. Dipper is given the opportunity to understand he cannot alter the future in such a drastic way without hurting those closest to him, thus giving his decision to learn to cope with an unchanged future that much more depth; however, Pete is left with an outcome that he neither expected nor can fully comprehend, leaving him more confused than he began and giving both him and viewers no satisfaction in the discovery. “The Time Traveler’s Pig” is more successful in presenting the hybridized fixed and dynamic timelines because, by the end of the episode, the amount of change its characters ultimately exerted is unimportant, but what truly matters is that they were given varying opportunities for introspection within these scenarios.