After a violent tremor shakes a Manhattan office building to its core, leaving only one survivor who leads the Fringe Team to believe he is not from this reality. Walter surmises that what shook the building was not geologic, but rather something discovered by him and William Bell many years ago. With another catastrophe imminent, the team races to Jacksonville, the site of Walter and William’s experiments, forcing Olivia to face her mysterious past in an effort to save hundreds of people from certain death.
When a specific group of guests at a wedding in Brookline, MA, suffocate from the inside out, the upsetting and disconcerting crime scene has the Fringe team investigating how the toxin was delivered and targeted. As evidence is taken into the lab, it’s discovered that the wedding ceremony was a testing ground for a weaponized science experiment. Adding to the intense lab investigation, Walter uncovers an alarming formula that reveals a link to a branch on the Bishop family tree. With the escalating threat of more deadly attacks and unexpected familial ties to the case, the Fringe team stops at nothing to prevent further catastrophic events.
When a man enters an office in Boston for a meeting, he becomes disoriented and collapses, only to have his veins erupt and spray blood everywhere. Shortly after Olivia and Peter arrive at the scene to investigate the bizarre case, it's discovered that a lethal virus with deep ties to something very valuable is spreading, so the CDC moves in to quarantine the building and eradicate the pathogens. Isolated inside with the rest of the exposed office employees, Peter and Olivia face life-threatening circumstances, sending Walter, Broyles and Astrid on a frantic search for a solution to save them.
Following an unexplained attack involving disfigured humans, the Fringe team visits Edina City, a small town in upstate New York to uncover leads surrounding the bizarre case. When it's determined that these disfigured people have managed to hide themselves for a while and they'll do just about anything to keep it that way, the investigation takes an unexpected turn.
After a teenage girl is pronounced brain dead, her mother takes her off life support, but when doctors operate quickly to remove her organs, the deceased girl shockingly awakens screaming an alphanumeric code. Equally as perplexing as her resurrection is that she is now somehow able to speak Russian and possesses classified information only a high-ranking soldier would know. While the girl's mind-bending condition intensifies, Walter dusts off some old lab videos and hypothesizes the unthinkable, sending Olivia and Peter to investigate the bewildering case.
A Fringe investigation is triggered when a patient at a mental institution undergoes an impromptu brain surgery that unexpectedly leaves his brain exposed. Despite the unthinkable circumstances, the patient’s condition and sanity miraculously improves before the Fringe team arrives. While Agent Dunham and Peter scan surveillance tapes (and Walter enjoys his pudding), Olivia recognizes a familiar face as Thomas Jerome Newton, the leader of the “shape-shifters.” As similar cases stack up, the Fringe team heads back to the lab to determine exactly how patients are being cured. Walter’s brains are put to the test and William Bell resurfaces.
After a cargo ship runs aground, the shoreline becomes littered with bodies hosting a giant squid-like creature. The Fringe team descends upon the scene to examine the bodies and discovers that the mysterious organisms are actually giant parasites. As the investigation unfolds, Walter heads back to the lab while Olivia, Peter and Broyles race against time when they realize the case has ties to a threatening organization.
A peculiar abduction occurs in Boston, leading the Fringe team to uncover details of the mysterious man known as The Observer. While the bizarre case takes center stage, Walter, Peter, and Astrid hit the lab to analyze unusual evidence and deal with Walter’s insatiable appetite for milkshakes.
When a kidnapping rapidly escalates into a hostage situation in New York, local authorities close in on the suspects only to discover that an unknowable force has mind-blowing consequences. The investigation intensifies and the mystery and threat deepen to unimaginable proportions when the Fringe Division identifies a link between the kidnapping and Massive Dynamic.
The Fringe Division takes on a puzzling investigation of victims who inexplicably disintegrate into ash. The shadowy case casts light on Special Agent Phillip Broyles’ past and leads the team to the possibility of foreign fringe science.