The critically acclaimed Fringe explores the ever-blurring line between science fiction and reality, where hybrid monsters tear through sewers, thieves walk through walls and portals open to parallel universes. Unable to police a world in which science has advanced beyond our wildest dreams - and nightmares - FBI Special Agent Olivia Dunham seeks help from eccentric 'fringe' scientist Dr. Walter Bishop and his jack-of-all trades son, Peter.
Under the direction of Special Agent Phillip Broyles and assisted by Agents Astrid Farnsworth, Charlie Francis and Lincoln Lee, the Fringe Team investigates unusual incidents that defy human logic and unimaginable events that threaten our very existence on a universal scale.
01 - Neither Here Nor There
The Fringe Team takes new shape as the impact of Peter's heroic choice unfolds in the fourth season premiere. 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.
02 - One Night in October
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.
03 - Alone in the World
When two 12-year-old kids bully another boy, they are found dead...and in just hours after dying, their bodies are shockingly in an advanced state of decomposition. As the Fringe team investigates the mysterious case, they uncover an amorphous figure claiming more victims. Meanwhile, Walter becomes increasingly distracted by his hallucinations.
04 - Subject 9
Olivia uncovers a dangerous force that may be connected to Walter's past experiments with the drug Cortexiphan. Their investigation forces Walter to leave the lab for the first time in years as he and Olivia head to Massive Dynamic in New York to examine old case files. Walter struggles with life outside the lab as he comes face-to-face with the demons of his past.
05 - Novation
Some things are not meant to be tampered with. In the aftermath of recent shocking events, things really escalate when the translucent shapeshifters return. As the threat and circumstances intensify, a former Massive Dynamic scientist Malcolm Truss (guest star ARYE GROSS) enters the fold. Meanwhile, Nina Sharp pays Walter a visit in the lab.
06 - And Those We've Left Behind
The Fringe team must find the pattern between tragic time loop anomalies. As the investigation unfolds, Raymond (guest star STEPHEN ROOT), an electrical engineer, and his wife Kate (guest star ROMY ROSEMONT), a professor of theoretical physics, enter the picture and time becomes a matter of life and death.
07 - Wallflower
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 mysterious migraines.
08 - Back to Where You've Never Been
The time has come to choose a side. In an effort to find a way home, Peter journeys to the Other Side to confront Walternate - a venture that proves more dangerous than expected. Meanwhile, Olivia receives a dire premonition from an Observer.
09 - Enemy of My Enemy
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.
10 - Forced Perspective
Olivia continues to cope with the ominous warning from the Observers, while Peter and the team track a girl with the mysterious ability to see the future and predict death.
11 - Making Angels
Our 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.
12 - Welcome to Westfield
Peter, Olivia and Walter come face-to-face with a mysterious and terrifying Fringe event as they become trapped in a town there's no escaping from.
13 - A Better Human Being
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.
14 - The End of All Things
Peter and the Fringe team take extraordinary measures in an attempt to stop life-threatening events from unfolding.
15 - A Short Story About Love
Following the recent shocking revelations and emotional events, Peter weighs his options as the Fringe team investigates a killer targeting love.
16 - Nothing As It Seems
The Fringe team faces a case that appears familiar to Peter. Strangely, it takes place in this world.
17 - Everything In Its Right Place
Lincoln travels to the other side to join forces with Bolivia and his own alternate, as they search for a vigilante with a surprising connection to the shapeshifters.
18 - The Consultant
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.
19 - Letters of Transit
The Fringe tradition of a mind-bending 19th episode continues as the Fringe team goes back to the future. Jumping ahead to 2036, the Fringe team and the Observers engage in a game-changing battle.
20 - Worlds Apart
The Fringe teams on both sides fight for a common cause as the Cortexiphan children surface with some shocking new developments.
21 - Brave New World: Part 1
A mysterious Fringe event, causing people to spontaneously combust, forces Walter to revisit his painful past while the Fringe team faces off against David Robert Jones to save the world - or worlds.
22 - Brave New World: Part 2
In the climactic conclusion of the two-part Season Four finale, the Fringe team is pushed to their breaking point as they desperately attempt to prevent a catastrophic event that threatens the lives of everyone.