FBI agent Olivia Dunham (Anna Torv) and Walter lead a team of former Cortexiphan test subjects to retrieve him, after discovering that Peter is an unwitting part of Walternate's plans to bring about the destruction of our universe using an ancient doomsday device.
The writers sought to emphasize the differences between the two worlds: Anna Torv created a unique personality and physical demeanor for her character's doppelgänger, Fauxlivia; DC Comics designed special covers based upon some of their classic editions to display in the Other Side.
The episodes mark the first appearance of recurring character Lincoln Lee (Seth Gabel), as well as the return of actors Leonard Nimoy and Kirk Acevedo as William Bell and Agent Charlie Francis, respectively.
To warn Peter of his impending role, the Fringe Division work with biotechnology corporation Massive Dynamic to come up with a way to cross over.
Peter reunites with his real mother, Elizabeth (Orla Brady), while Walter's team journeys to meet with William Bell (Leonard Nimoy) at Central Park.
Olivia follows her alternate counterpart and encounters Bell, who insists he did not betray their location to the Fringe Division and tells her that Walter is in trouble.
[15][16] Pinker explained the idea of two worlds: "One of the big themes of the show is how small choices that you make define you as a person and can change your life in large ways down the line."
[33] Torv wanted to make the new character "completely different", but she and Goldsman recognized that the two share some major similarities, as they both are in the same profession and are "fundamentally, genetically really the same person.
[34] Pinkner describes shooting the Fauxlivia scenes in the DVD audio commentary: "When [Torv] first showed up on set in this different guise, she had really embodied this other character in a very playful and sexy way.
[42] The scene between Olivia, Walter, and Bell was originally set in a coffee shop, but the producers changed their minds when they realized they needed more funding for the finale.
[15][46] They were originally going to have Olivia sacrifice herself to allow Peter and Walter's return to Our Side, but changed their minds when Wyman suggested she be secretly swapped with Fauxlivia instead.
[6] On April 5, 2010, Entertainment Weekly reported that Dirty Sexy Money actor Seth Gabel had been cast as the lead Fringe investigator in the parallel universe, and would be making his first appearance in the finale as a possible recurring character.
"[25] In an interview with TV Guide, Gabel commented that during shooting he felt that he looked "like such a doofus holding a gun," but changed his mind when he saw the finished production.
[60][61] The actor, the producers, and some fans have called the new character "Scarlie" in reference to a scar on his cheek, which takes ten minutes to apply before shooting, according to Acevedo.
"[67] Nicole based "alterna-Astrid"'s characteristics on her sister, who has Asperger syndrome, partly by avoiding eye contact with the other characters when relaying information to them[68] and by focusing solely on the data in front of her.
Pinkner commented that Nimoy's retirement from acting obviously hinders his character's possible return but, "if Leonard chooses to come back, there is a story in place that we'd love to tell.
[24] When the producers told Nimoy their ideas for Bell's storyline in the third season, he returned for some brief voice and animation work in the episode "Lysergic Acid Diethylamide".
The American drama series The West Wing is beginning its 11th season in the parallel universe,[60][76][77][78] and US politicians Barack Obama and Sarah Palin are in one of the show's advertisements.
[60][80][81] The Hotel Attraction project by Spanish architect Antoni Gaudí was built in 1908 in the parallel universe, whereas in our world it never went past initial planning.
[10][60][77] Aviator Charles Lindbergh is less well known in the parallel universe, and the famous kidnapping of his son presumably did not occur, as Fauxlivia expresses confusion when his name is brought up.
[85] Other films, both real and invented, are also shown in the parallel universe, such as Superman vs. Batman 2, Indiana Jones and the Hex of the Hydra, Star Wars: Legion of Droids, Splash 7, Smokey and the Bandit: The Final Lap and Mask vs.
"[96] The second part's purpose was for "students [to] learn about how various types of sensors can be used to remotely collect information about a geographical area, which allows for unique scientific analyses and discoveries.
[98][99] In keeping with the rest of its second season,[100] Fringe's ratings suffered due to tough competition from episodes of CBS's CSI: Crime Scene Investigation and ABC's Grey's Anatomy, as these programs were also broadcast in the same time slot.
Ramsey Isler of IGN thought it "fantastic," because it was "a great story that leads us into one hell of a conclusion to the season," and that it "right away [gave] us the deepest, most exciting look into the alternate universe we've seen so far.
"[60] Critic Andrew Hanson, writing for the Los Angeles Times, noted that because of the parallel universe focus, the first part felt like the following season's premiere.
[78] MTV's Josh Wigler praised Torv's performance, but wished the two-part finale was not broken up, explaining "I could have easily tuned in for another several hours.
He was "kind of torn" on the Peter-Olivia kiss, wished Peter and the doomsday device had been set up more for the third season, and believed the Olivia-Fauxlivia interaction to be "a little strange," as the two went from discussing their respective families to "ass kicking".
[11] Ken Tucker praised the acting and the writers, noting "The fact that the series can accommodate a fan like me only confirms what a well-wrought piece of pop culture Fringe has become.
"[109] James Poniewozik from Time Magazine positively compared both parts of the finale to The X-Files, writing that, unlike that series, Fringe's standalone episodes contribute to the overall mythology of the show.
[11][109][110][111] Website blogger io9 listed both parts of "Over There" as one of the select few "crucial" episodes new viewers must watch to understand the show, referring to it as "one of the most epic season finales ever".