Subject 13 (Fringe)

In the parallel universe, Walternate's (Noble) position as national security czar makes Peter's disappearance a major news story.

Walter puts Olivia under several tests to try to coax her to cross over, eventually eliminating all emotions but fear as the triggering mechanism.

Olivia, in tears, hands Walter the sketchbook, explaining about her stepfather's abuse and that she knew she had crossed over to the parallel universe.

[3] In an interview with TV Guide, Pinkner and Wyman revealed they had known Olivia and Peter met as children for a long time, but did not decide to show this to the audience until they wrote the episode.

Wyman described Elizabeth Bishop's successful lie at making Peter believe she is his real mother as "the beginning of the end for her,"[4] as her character will ultimately commit suicide.

In early January 2011, TVLine's Michael Ausiello exclusively reported that Fringe was casting for an actor to play the part.

[6] Several news sources later in early March noticed on the Internet Movie Database that actor Chris Bradford had been cast.

[17] In the parallel universe, Walternate is credited with making the Star Wars program work, leading to his role as the national security czar.

[16] One of the other identified students at the daycare center is Nick Lane, whose adult character appears in the episodes "Bad Dreams" and "Over There".

It retained similar viewership from the previous week's episode, "6B", with an estimated 4.0 million viewers and a 1.5 ratings share among those aged between 18 and 49.

Andrew Hanson from the Los Angeles Times called it one of his favorite Fringe episodes due to the "incredible" opening, Brady and Noble's "outstanding" performances, and the scene with Olivia unknowingly talking to Walternate.

[1] Like Hanson, Ken Tucker from Entertainment Weekly also praised the actors' performances, and thought it was "one of the most moving and revelatory episodes in the series' short history".

[18] Finally, he thought the scene in which Olivia accidentally encounters Walternate was a "brilliant plot twist that ties a lot of things together".

Club graded the episode with an A−, explaining that, like the other reviewers, he loved the opening sequence with Peter on the lake, the newest mythology details, as well as how Walternate discovered the prime universe.

[3] Murray also loved the "mood" of the episode, but had minor problems with the plot, as he thought it was now harder to believe Olivia, Peter, and Walter were strangers to each other in the first season.

[3] James Poniewozik of Time magazine concluded that the episode "was not the revelation that 'Peter' was, though a phase-shifting Olivia’s mistaking of Walternate for Walter was one of the series’ most mindblowing moments (and, again, a Lostian bit of disorienting sleight of hand).

'Subject 13' is also one of the great parallel universe episodes, too, charting the shattering impact of Peter's abduction on both sets of Walter and Elizabeth (Orla Brady).

Chandler Canterbury ( pictured ) replaced Quinn Lord in portraying Young Peter Bishop .
Critics praised the performances of John Noble ( pictured ) and Orla Brady .