第 4 季 共 22 集
播出时间：2011年9月24日
第 1 集 Neither Here Nor There
播出时间：2011年9月24日
Just one week after Peter Bishop saved the day and was then wiped from existence, the truce between the two worlds remains intact and the two sides are forced to work together. Lincoln Lee joins the Fringe team as they investigate a shapeshifter case that is very personal to him.
第 2 集 One Night in October
播出时间：2011年10月1日
As the victims of a highly intelligent serial killer "Over There" stack up, the Fringe Division "Over Here" is asked to assist. As the two sides tangle and innocent people remain at risk, the suspect's doppelganger "Over Here," a professor who teaches Forensic Psychology, is brought into the fold and forces the team to consider the notion of sending civilians to the other side
第 3 集 Alone in the World
播出时间：2011年10月8日
Two young bullies are found dead and in just a few hours they rot to an advanced state of decomposition. The Fringe team investigates and uncovers an amorphous figure claiming more victims. Walter becomes increasingly distracted with his mental state.
第 4 集 Subject 9
播出时间：2011年10月15日
Olivia uncovers a dangerous force that may be connected to past experiments with Cortexiphan. The investigation forces Walter to leave the lab for the first time in years and travel to Massive Dynamic to examine old case files. Walter struggles with his emotional state as he confronts the demons of his past.
第 5 集 Novation
播出时间：2011年11月5日
Olivia and the others of Fringe division attempt to determine the origin of Peter Bishop, who purports himself as Walter's son who had died as a young boy in the original time line.
第 6 集 And Those We've Left Behind
播出时间：2011年11月12日
The Fringe team must find the pattern between tragic time loop anomalies. As the investigation unfolds, Raymond, an electrical engineer, and his wife Kate, a professor of theoretical physics, enter the picture.
第 7 集 Wallflower
播出时间：2011年11月19日
When a man mysteriously dies by an invisible force, his body rapidly begins turning ghostly white. The Fringe team learns that this is not an isolated incident, and there’s evidence that links the predator to someone who passed away with an unknown genetic disorder. Meanwhile, Olivia suffers from migraines.
第 8 集 Back to Where You've Never Been
播出时间：2012年1月14日
In an effort to find a way home, Peter journeys to the Other Side to confront Walternate. However, his venture proves more dangerous than expected. Meanwhile, Olivia receives a dire premonition from an Observer.
第 9 集 Enemy of My Enemy
播出时间：2012年1月21日
Peter's visit to the other side intensifies as the alternate FRINGE division faces off against a formidable new foe in a harrowing race against time.
第 10 集 Forced Perspective
播出时间：2012年1月28日
Olivia continues to cope with the ominous warning from the Observers, while Peter and the team track a girl with the mysterious ability to predict death.
第 11 集 Making Angels
播出时间：2012年2月4日
Over Here Astrid gets an unexpected visit from her Alternate, while Peter and Olivia track a killer using a toxin that has yet to be invented. Both universes collide in a case that pushes the boundaries of what is possible.
第 12 集 Welcome to Westfield
播出时间：2012年2月11日
Peter, Olivia and Walter come face to face with a mysterious and terrifying Fringe event as they get trapped in a town that there’s no escaping from.
第 13 集 A Better Human Being
播出时间：2012年2月18日
As the Fringe team investigates a mentally ill patient who appears to be connected to a series of murders, frightening clues and connections are uncovered that lead Olivia to some shocking revelations.
第 14 集 The End of All Things
播出时间：2012年2月25日
The dying Observer comes to see Walter and Peter, who must take extreme measures to learn what secrets he hides and determine if he knows where Olivia is. Meanwhile, David Robert Jones tries to force Olivia to use her cortexiphan abilities by torturing Nina.
第 15 集 A Short Story About Love
播出时间：2012年3月24日
Following the recent shocking revelations and emotional events, Peter weighs his options as the Fringe team investigates a killer targeting love.
第 16 集 Nothing As It Seems
播出时间：2012年3月31日
The Fringe team faces a case that appears familiar to Peter. Strangely, it takes place in this timeline.
第 17 集 Everything in Its Right Place
播出时间：2012年4月7日
Lincoln travels to the other side to join forces with Fauxlivia and his own alternate, as they search for a vigilante with a surprising connection to the shapeshifters.
第 18 集 The Consultant
播出时间：2012年4月14日
Walter travels to the Alternate Universe to assist in the investigation of a Fringe event with ties to both worlds. Meanwhile, David Robert Jones reveals his next target.
第 19 集 Letters of Transit
播出时间：2012年4月21日
The Fringe team goes back to the future as the story jumps ahead to 2036, when the Observers and the Fringe team engage in a game-changing battle.
第 20 集 Worlds Apart
播出时间：2012年4月28日
The teams on both sides fight on for a common cause, and there are shocking developments tied to the Cortexiphan children.
第 21 集 Brave New World (1)
播出时间：2012年5月4日
Walter is forced to revisit his painful past when a fringe event causes people to spontaneously combust; the team faces off with David Robert Jones.
第 22 集 Brave New World (2)
播出时间：2012年5月12日
The Fringe team is pushed to the breaking point as they desperately attempt to prevent a catastrophic event that threatens the lives of everyone.
