Olivia is the series' protagonist, and was introduced as an FBI Special Agent, working for a multi-agency task force of the U.S. Department of Homeland Security called the Fringe Division, dealing with supernatural events that are linked to experimental occurrences.

Olivia's perspectives and inner feelings seemed to make her life harder for her but very often serve as the focal points for episodes of the series that directly focus on her development as a human being and a member of the law enforcement community.

Following a plot line in the second season, viewers are introduced to Olivia's doppelgänger from the parallel universe, which develops an alternate reality for each character.

[2] With help from Walter, Olivia finds a way to communicate with John within her mind, eventually allowing the memories to fade completely.

[3] Olivia is revealed to be linked to the drug Cortexiphan, a chemical developed by William Bell, which supposedly allows children injected with it to retain higher brain functions which would normally deteriorate with age.

As a result, Olivia is capable of unspecified psychic abilities, as demonstrated when she shuts off a series of lights wired into a bomb as a kill switch simply by thinking of it.

When Olivia regains part of her memories of her meeting with Bell, she is told that she is the only successful subject suitable to pass through dimensions without many known negative side-effects.

[7] Olivia is given permission by Nina Sharp to meet William Bell, who currently resides in another dimension, with his office in the World Trade Center's South Tower.

It is revealed that the alternate Walter plans to use Olivia's Cortexiphan-derived abilities to find a way to safely cross universes, for which he needs her willing assistance.

However, Olivia begins to regain her past memories after she has hallucinations of Peter Bishop, who comes to her in a vision and tells her that she doesn't belong there before kissing her.

[14] They begin dating and their relationship is progressing when Walter realizes he has brought back William Bell, who died in the alternate universe, by using soul magnets and he now resides in Olivia's mind.

[1] She was unable to finish him off, and so he recovered and disappeared, leaving her to blame herself for not exacting retribution against him, contributing to her determination to bring criminals to justice.

[23] She was nine years old when she shot her stepfather, and she states in an earlier episode that she knew what she wanted to do for a career "pretty much since [she] was nine", indicating a direct link between the childhood abuse and her job.

In the reset timeline for the series' fourth season, Torv explained that "The Olivia we meet and know has known about Fringe Division and had all this time to get used to it and work out that this is her life," rather than becoming familiar with it after the attack on John Scott.

[1] Olivia was involved in a serious relationship with fellow FBI agent John Scott,[1] and his supposed betrayal and death was something she dealt with for much of the first season.

"[26] Torv and Akiva Goldsman discussed various ways to differentiate the two depictions of Olivia;[27] ultimately two different physical demeanors were created.

[28] 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.

[30] 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.

[34] IGN's Travis Fickett agreed, calling Torv's early work on Fringe "very good" as she "brings a unique presence to the show.

"[36] Conversely, SFScope columnist Sarah Stegall believed Torv's early performance to be "downright wooden",[37] while others criticized the actress and character for being "cold and distant.

"[38] The New York Observer found her to be the one weak link of the main cast, criticizing Torv for her accent and for showing "less emotion than a piece of plywood.

"[39] In a response to some early negative reactions to the actress' performance, Jon Lachonis noted in a review of the first season's seventh episode that "Anna Torv, whose chill portrayal of FBI agent and Pattern investigator Olivia Dunham has come under fire for being too wooden, seems to have reinvented her character to answer the critics.

Wyman defended Torv's early Fringe work in a 2011 interview, explaining the character was designed to be "bland, because of her conditioning as a child and everything she's been through.

[41] Midway through the second season, Sarah Stegall from SFScope believed Torv "had the most progress and the most satisfying development" of all the main actors, stating she "is now carrying this role with grace and strength".

[37] Stegall partly attributed the growth of the actor and character to her recovery early in the second season, the introduction of a sister and niece, the removal of John Scott from her storyline, and the "delicate, reserved flirtation" with Peter.

[42] TV Guide called it one of the best performances of the year, explaining "Switching Olivia with her alternate-universe self... jump-started the show's interpersonal dynamics — and changed the way we look at Torv.

While some credit goes to the writing, it was Torv's shaded performance that sold Olivia's alternate-universe twin as an actual separate person—not just a cartoon villain version of the original, but a real person, a little more assertive and confident, and just a touch rapacious.

Meanwhile, she convincingly portrayed the trauma and confusion of her captured-then-returned Olivia, whose emotional (and complicated) reunion with Peter made an outlandish situation real and moving.