The second season of the American science fiction television series Fringe commenced airing on the Fox network on September 17, 2009, and concluded on May 20, 2010. The season was produced by Bad Robot Productions in association with Warner Bros. Television, and its showrunners were Jeff Pinkner and J. H. Wyman. Actors Anna Torv, John Noble, and Joshua Jackson reprised their roles as FBI agent Olivia Dunham and father-son duo Walter and Peter Bishop, respectively. Previous series regulars Lance Reddick, Jasika Nicole, Blair Brown, and Kirk Acevedo also returned, though with Acevedo in a limited capacity.
The season followed the continuation of a war between two universes, the prime and the parallel. It was set in the former, until the last several episodes when Peter Bishop (Jackson) journeyed back to the parallel universe after being lured there by his real father, “Walternate” (Noble). While co-creator J. J. Abrams described the first season as “identifying that there is an enemy”, he referred to season two as “getting to know the enemy” as it “build[s] to a very specific type of confrontation” between the two universes. The writers focused on their characters’ development, in particular making them more comfortable with each other while solving cases for Fringe Division. By inventing the “mythalone” style of episode, the producers sought to create the perfect episode that mixed standalone episode qualities for casual viewers with the further development of the series’ mythology for regular viewers.
In a departure from the previous season, the second season aired in a new competitive timeslot at 9:00 pm on Thursdays. It contained 22 episodes, plus an unaired episode that was produced during the first season; “Unearthed” aired as a special as episode 11 of season two, days prior to “Johari Window“, the first new episode of 2010. Also part of the season was the series’ only musical episode, “Brown Betty“, which was produced at the request of the network. The season finale, “Over There“, fully introduced the parallel universe and laid the groundwork for the third season.
Fringe ended its second season with a per episode average of 6.252 million total viewers and a 2.3 ratings share in the 18–49 demographic. The season was generally well-received by critics, though most agreed that the second half was a considerable improvement over the first. The series was chosen for a number of 2010 “best of television” lists, including The New York Times, the Seattle Post-Intelligencer, and Entertainment Weekly. Despite its critical acclaim, Fringe failed to earn any major category nominations at the 62nd Primetime Emmy Awards, but did receive nominations at the Creative Arts Emmy Awards, Golden Reel Awards, and Satellite Awards; at the Saturn Awards, Torv and guest actor Leonard Nimoy won in their respective categories. The second season was released on DVD and Blu-ray in region 1 on September 14, 2010, in region 2 on September 27, and in region 4 on November 10.
Olivia, having been taken to William Bell’s office in the parallel universe, is returned to the prime universe but with short term amnesia, unable to recall her experience there. Massive Dynamic’s Nina Sharp directs her to Sam Weiss, a bowling alley manager, who gives her cryptic but helpful advice to overcome her amnesia. Meanwhile, the Fringe division has discovered several shapeshifters – a human/machine hybrid that bleed mercury – have crossed over, but unbeknownst to them, one takes the form of Olivia’s partner, Charlie. When Sam’s advice allows Olivia to recall what Bell told her, she unwittingly gives this information to the shapeshifter, who calls its agents to use the information to recover the body of Thomas Jerome Newton, an agent for some entity operating from the parallel universe. Nina provides Olivia with cautionary advice, alerting her to a “great war” that Bell postulated would occur between the two universes. During this time, Peter has come to forgive Walter for his past, and Walter has grown accustomed to normal life outside of the institution, but is still troubled by a secret.
Newton, using old technology from Walter and Bell’s research, is able to pull an entire building from the parallel universe to the prime, and the team races against time to prevent harm when, due to the laws of mass conservation, a building from the prime is pulled to the parallel one. This event forces Walter to try to coax Olivia to recall her Cortexiphan abilities as to identify things affected by the parallel universe. Initially unable to do so, her fear of failure enables her ability, allowing them to save the people within the target building, but also revealing to her that Peter is from the parallel universe. Walter explains to Olivia that in 1985, he and Bell had devised a way to observe the parallel universe, where he found his doppelgänger, “Walternate”, was also close to losing his son. Though Walter’s Peter had died, Walternate continued to search for a cure, but missed the telltale sign when the Observer September arrived at his lab. Walter resynthesized the cure and aimed to cross over using untested equipment at Reiden Lake, though stalled by Nina and his lab assistant Clara. Nina tackled him on his way over, losing her arm in the process, while Walter, on the other side, found the cure vial broken. Intent on curing the alternate Peter, he posed as his father and crossed back with Peter, intending to administer the cure at the lab and then return Peter. However, on the return, the ice on Reiden Lake broke, threatening to drown both, but they were saved by September, who cautioned Walter “the boy must live”. While Walter successfully administered the cure, his wife Elizabeth saw Peter, and Walter realized he could never return Peter to the parallel universe. After Walter reveals this truth, he considers letting Peter know but struggles with how to do so, hoping to seek repentance from God for his actions.
Meanwhile, Newton has continued to use Walter’s technology to bring into temporary existence elements from the parallel universe. This enables Newton and his agents to bring over a figure known as “Mr. Secretary”, despite Fringe’s attempts to stop them. Peter, from this action, deduces that he is from the parallel universe, and furious at Walter for hiding this information, leaves on his own. While hiding in the Pacific Northwest, Peter meets Mr. Secretary – Walternate, his true father, who offers to take him back to the parallel universe, which Peter accepts. Olivia and Walter are alerted by September that Walternate plans to use Peter to initiate the operation of a strange device that threatens to destroy the prime universe, and the two launch a rescue attempt. In the parallel universe, they find that it suffers from singularities caused by Walter’s crossing in 1985, forcing Walternate’s Fringe team to use an amber-like substance to surround and quarantine such areas, regardless of innocent lives trapped within. They meet with William Bell, and Walter and Bell resolve their past differences. Olivia faces off against her doppelgänger, “Fauxlivia”, who works for Walternate in the Fringe Division under the U.S. Secretary of Defense; she is able to recover Peter, who has seen the device and recognized that it reacted only to his biology, and wants nothing of it, willing to return with the others. As Olivia, Walter, and Peter attempt to return, they are engaged by Fauxlivia and others in the Fringe Division. Bell sacrifices himself to provide energy into a device to allow the three to cross over, but none of them are aware that Fauxlivia has secretly switched places with Olivia under Walternate’s orders, while Olivia is captured and held in a secured facility by Walternate.