During the five-season series, the mythology and backstory of the show expanded across a broad spectrum of recurring themes (such as alternate realities and timelines), locations, and characters to serialize story arcs and intricately link early episodes with later ones.
[1][2] Massive Dynamic is a fictional, multi-faceted conglomerate working for the advancement of weapons testing, robotics, medical equipment, aeronautics, genetics, pharmaceuticals, communications, energy, transportation, and entertainment technology.
Initial exposure to the drug as an adult can be lethal, so trials were performed on children in at least two locations, including a day-care center in Jacksonville, Florida, and at the Wooster Campus of Ohio State University.
[8] Other changes exist in the parallel universe's popular culture; Eric Stoltz stars in Back to the Future,[8] the musical Dogs has replaced Cats as the longest running Broadway musical, the Sherlock Holmes books were never written, and many comic book characters are different or do not exist such as Green Lantern being Red Lantern and Batman being the Mantis.
In trying to track down David Robert Jones, Olivia discovers that a large number of events studied by the Fringe division point to the fictional Reiden Lake in New York.
Due to an attempt by Nina Sharp to stop him from using the untested device, Walter lost the cure, and instead brought Peter back to the prime universe to administer a new batch, intending to return the child.
[2] The "last great storm" is a concept attributed to William Bell by Nina Sharp in "Momentum Deferred" with regard to the two parallel universes and the likelihood that one or the other would be destroyed once the doorway between them was opened.
The conflict, a product of the Pauli Exclusion Principle, means that no two objects can occupy the same space at the same time, which arises as a direct result of Walter's initial abduction of Peter from the parallel universe.
As shown in the events of "Subject 13", Walternate is unable to explain how his son had disappeared despite being the United States Security Czar, and only when young Olivia temporarily enters the parallel universe under emotional stress does he come to realize its existence.
Such events are shown to come to pass in the future Peter witnesses while using the Machine in "The Day We Died", in which the parallel universe had been fully obliterated by the singularities.
Yet another great storm, if not the original one, appears in season four when David Robert Jones (alive in the adjusted timeline) tries to destroy the universes through use of the Cortexiphan subjects and by other means.
ZFT, an acronym for the German phrase Zerstörung durch Fortschritte der Technologie, literally translated as "Destruction through Advancement of Technology", is a cult-like group of agents working to open a gateway between the two universes regardless of the cost, and are featured as the primary antagonists in the first season.
The cult follows the ZFT manifesto, a document describing how to open a gateway between universes, apparently written by Walter before his period at the mental institution.
Extensive quantities of amber have been used: notable examples include the entire area around Madison Square Garden ("Over There"), and a large portion of the city of Boston ("Over There", "Entrada").
Despite the fact that this action created an alternate timeline, the bridge remains opens for most of season four until the two universes are forced to close it due to David Robert Jones trying to use it to destroy them both.
William Bell had collected the five First People texts and recognized Sam Weiss as the descendant of the author, and requested Nina Sharp to treat him as a special adviser in these matters.
In "The Day We Died", it is revealed that the First People are future versions of Walter and some others including Astrid and Ella, having sent the deconstructed Machine through a wormhole in New York City to the far-distant past.
When Peter re-emerges in the timeline, his influence restores their previous dynamic, though only Olivia eventually regains her memories in the episode "A Better Human Being" through the use of Cortexiphan.
The original timeline is suggested to be a version of reality where the Observer known as September (Michael Cerveris) never distracted 7-year-old Peter (Quinn Lord)'s scientist birth father, Walternate (John Noble) from curing his childhood illness to save his life.
A 32-year-old Peter's consciousness is driven forward fifteen years in the closing moments of the season three penultimate episode "The Last Sam Weiss" after he steps into the machine—also known as the Doomsday device—in the prime universe.
After the producers reassured that Walter's crossover origin story remained intact,[20] the episode "Novation" showcased the point of divergence in the timeline without Peter growing up.
[20] After September allowed Peter to drown, Elizabeth Bishop (Orla Brady) immediately committed suicide fifteen years earlier (mentioned in "The Man from the Other Side") in 1985 from the grief of losing her son twice (altered in "Back to Where You've Never Been").
Following this, Olivia took on some of Nina's hobbies like horseback riding (seen in "The Cure") in her teenage years (seen in "Novation" and "Forced Perspective") while Rachel still met Greg and gave birth to Ella (Lily Pilblad), though their marriage remained intact and they had a second child named Eddie ("Nothing As It Seems").
These events only occurred when Walternate became aware of her abilities from the Peter-influenced confession she made as a child ("Subject 13"), leaving the cases she solved in the parallel universe unresolved, such as predictive criminal Milo Stanfield (Michael Eklund).
"One Night in October" reveals Fauxlivia still lived with her boyfriend Frank (Philip Winchester) who had broken up with her after discovering she was pregnant with Peter's child ("Immortality"), though they later separated in the new timeline for undisclosed reasons ("The Consultant").
Olivia also never met any Cortexiphan subjects as an adult until Cameron (Chadwick Boseman), meaning Nick was recruited by Jones earlier in the timeline than the events of "Bad Dreams".
Etta Bishop helps to regenerate Walter's brain with pieces that were previously removed by William Bell and stored at Massive Dynamic ("Letters of Transit", "Brave New World").
However, considering Walter's habits of documentation, the Fringe team sneaks into Harvard, now converted to an Observer base, and discover that some of the tapes are embedded in the ambered part of the lab.
They carefully and slowly extract each tape, and follow the directions to recover the items cited, during which they come to learn that Walter was aided by an unseen figured named "Donald".
September is located - having his Observer implant stripped and undergone a "biological reversion" to become a normal human - and he explains that with the components they have collected, the plan would be to send Michael into the future of 2167, hoping that the researchers working on the gene program would see that it is possible to possess both emotion and intelligence, and put an end to the experiment.