The series follows a Federal Bureau of Investigation "Fringe Division" team based in Boston. The team uses unorthodox "fringe" science and FBI investigative techniques to investigate a series of unexplained, often ghastly occurrences, some of which are related to mysteries surrounding a parallel universe.
When a serial kidnapper “over there” strikes again, the emotional and familiar case hits home for Colonel Broyles, sending a determined Olivia to uncover additional details about the abductions. In the meantime, Olivia fights on and reunites with Henry to enlist his services on an intense and covert mission to return home.
Peter struggles to cope with recent events; Olivia searches for an ally; a device that communicates between universes is discovered...
When the Fringe Team investigates a case where a victim had his heart extracted, it’s just the beginning of a series of mysterious and reanimating events tied together. Meanwhile, Peter comes to terms with the reality of his relationship with Olivia.
An Observer makes contact with the Fringe Team to help rectify a mistake. Meanwhile, Walter befriends Roscoe Joyce, keyboardist for Walter's favorite 1970s band, "Violet Sedan Chair." Walter will learn the real reason the band broke up, and realize that the lives of these two men, who have never met before, overlap in strange and unexpected ways.
When the Fringe Team visits Massive Dynamic’s assembly of the doomsday device, Walter becomes greatly concerned for Peter’s well-being, so he turns to Nina for added brain power to understand the relationship between Peter and the superweapon. Meanwhile, the discovery of a dead body triggers an intense investigation.
When a scientist falls dead after ingesting a lethal cloud of blue powder and his bones disintegrate in his body, the CDC suspects a biological attack. As the Fringe Team investigates further, a subject from Walter’s past with ties to Olivia reluctantly agrees to assist with the intense case.
As the story shifts back to life “over there,” the absence of Colonel Broyles changes the dynamic of the Fringe Team as they investigate a bioterrorist armed with an insect that has a taste for human flesh. Meanwhile, alternate Olivia is reunited with her beau, and Walternate remains determined to save his world but discovers there are certain lines he will not cross.
A series of Fringe events leads the team to the home of a woman grieving over the death of her husband, while Peter and Olivia make an effort to repair the emotional rift between them.
In a follow up to last season’s “Peter” flashback episode, the all-new “Six Months Later” episode revisits a poignant period of time for both the Bishops and Olivia.
The Fringe Team investigates a group of thieves who can break the laws of gravity. Meanwhile, Walter attempts to delay the damage he's caused to the fabric of the universe.
When the Fringe team investigates an apparent suicide victim, they uncover a second set of fingerprints leading them to a woman with uncanny characteristics that cannot die.
The intensity of life “over there” accelerates as Olivia finds herself in mortal danger.
In an effort to remove Bell's consciousness from Olivia's mind, Peter, Bell, and Walter enter Olivia's subconscious and attempt to find her personality, which has hidden itself somewhere safe.
As devastation spreads on This Side, Walter, Olivia, and Sam Weiss struggle to find a way to stop the destruction and discover that one individual has the ability to allow Peter access to the Machine.
The Fringe team - preserved in amber for 20 years - is now a rebel resistance team fighting for freedom. Peter, reunited with his now adult daughter, Etta, sets out to find out what happened to his wife and Etta's mom - Olivia - as they start their mission to save the world from the Observers.
The Fringe team revisits the Harvard lab, now under Observer control, to try to find the information they need as the team fights on in their mission to save the world.
As the rogue Fringe team continues to fight off the oppressive Observers’ invasion, unforeseen events lead them into a forest where they encounter a strange subculture of people devoted to recording human history.
When the Fringe team tracks a lead into a hostile and heavily guarded location, Phillip Broyles resurfaces... but can he be trusted?
The Fringe team responds to recent devastating events, and a key member makes a pivotal and shocking move.
A Fringe team member takes on a new role, and Walter follows leads to a key piece needed in the battle against the Observers.
As the fight for the future intensifies, a member of the Fringe team orchestrates a Fringe event of his own.
Olivia encounters a very intuitive and oracle-like person named Simone as she looks to recover a key piece of equipment for Walter. Meanwhile, Peter finds himself in a perilous situation as he observes Windmark.
In attempt to recall a plan to defeat the Observers, Walter takes an LSD trip down memory lane. Meanwhile, Peter and Olivia trace a mysterious signal to the woods, where they come upon a grisly scene.
The Fringe team is running out of time to save the world. As Peter, Olivia, Astrid and Walter scramble to tap into a key piece of the puzzle to defeat the Observers, they enlist the aid of Nina Sharp who conjures up a plan.
As time dramatically ticks down, Peter, Olivia and Walter stop at nothing to save the universe from Observer rule. Walter enters the infamous deprivation tank in an attempt to uncover a key piece of information about the mysterious figure, Donald. Meanwhile, Captain Windmark sets out on a revealing mission of his own as long-standing questions are answered.
The Fringe team engages a desperate plan as Olivia embarks on a dangerous and otherworldly journey into the unknown.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Following the recent shocking revelations and emotional events, Peter weighs his options as the Fringe team investigates a killer targeting love.
The Fringe team faces a case that appears familiar to Peter. Strangely, it takes place in this timeline.
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.
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.
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.
The teams on both sides fight on for a common cause, and there are shocking developments tied to the Cortexiphan children.
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.