Olivia, still trapped in the Other Side and brainwashed, investigates the Rose brothers, who are able to do the seemingly impossible: escape from an amber-like substance used to contain fringe events.
Throughout the episode, she willingly participates in Walternate's tests in a sensory-deprivation tank located on Liberty Island to stimulate her Cortexiphan abilities.
Joshua had previously caught Fringe Division's attention as he used a molecular destabilization device to break into banks, triggering quarantine-level events.
Colonel Broyles is privately cautioned by Walternate that those trapped in amber are still alive, a fact he does not want to be made public for fear of an outcry.
Matthew escapes the quarantine while Fringe agents Charlie and Lincoln rescue Olivia in time before the amber sets in.
Co-executive producer Josh Singer and story editor Ethan Gross co-wrote the episode, while David Straiton served as the director.
[5] Seth Gabel and former series regular Kirk Acevedo reprised their characters Lincoln Lee and Charlie Francis, Fringe Division agents from the Other Side.
The tank Walternate uses to submerge Olivia has been noted by some critics to closely resemble a similar device in the 1980 science fiction film Altered States, which also starred Fringe actress Blair Brown.
[15] Walternate tells Broyles he first began the amber protocol on October 17, 1989, which was the same day as the 1989 Loma Prieta earthquake in our side's San Francisco Bay region.
[19][20] Den of Geek columnist Billy Grifter attributed the low ratings to the parallel universe focus, commenting "if you weren't a fan beforehand, you'll not be able to follow what's going on now.
A plot device from the first season now emerges as a major player in the Red universe stories; a passing moment of trivia between Nina and Olivia now takes on enormous significance in the snow globe.
This level of characterization, attention to detail over three seasons, and depth of plotting makes Fringe a classic, a show which is hitting its stride."
[3] Despite this, Murray thought the episode was "essential viewing" for Fringe fans due to certain revelations, such as how people are actually alive in the amber, and also because it moved the plot closer to an Olivia-Altlivia confrontation.
[23] Ken Tucker from Entertainment Weekly thought the episode was "enthralling," and he enjoyed the brothers' "nice emotional story," and praised Anna Torv's acting.
"[21] Grifter praised the Ashmore brothers' acting as well as their characters' storylines, calling their switch "a nice twist that's cleverly played".