waterlilybarb

Episode 1: Neither Here Nor There
FBI agent Lincoln Lee insists on helping Olivia investigate a series of killings by a translucent man who left his victims in the same condition. Meanwhile, the two worlds exchange information and Walter is haunted by visions of a mysterious man in his mirrors.

Episode 2: One Night in October
A serial killer on the Other Side has killed 23 victims and Fauxlivia comes to This Side to ask for the loan of the serial killer's duplicate, a mild-mannered Forensics Psychologist. Meanwhile, Walter deals increasingly vivid hallucinations.

Episode 3: Alone in the World
A 12-year-old boy makes an unusual friend, a friend who causes the death of two bullies. While the Fringe team attempts to deal with a growing field of contagion, Walter takes drastic measures to deal with his hallucinations.

Episode 4: Subject 9
When a bizarre energy mass attacks Olivia, she turns to Walter for help. When they realize the attack is related to Walter's Cortexiphan experiments on Olivia, they track down another test subject who had the ability to project his astral self.

Episode 5: Novation
While Olivia and Walter attempt to deal with the appearance of the man from their dreams, Fringe Division deals with a shapeshifter who is tracking down a former Massive Dynamic scientist in the hopes of getting him to stabilize her metabolism.

Episode 6: And Those We've Left Behind
Time anomalies apparently connected to Peter's arrival start manifesting in the Boston area, but the Fringe team soon discovers that they are caused by a husband desperate to be reunited with his ailing wife.

Episode 7: Wallflower
The Fringe team investigates a man with a broken neck who was drained of his pigmentation. Meanwhile, Olivia suffers from headaches and Peter begins trying to recreate the Machine.

Episode 8: Back to Where You've Never Been
Peter asks Olivia to help him go to the Other Side and ask Walternate for help when Walter refuses to help him employ the Machine to return to his own timeline. Meanwhile, the threat of the prototype shapeshifters grows and an old enemy returns.

Episode 9: Enemy of My Enemy
Peter reaches an uneasy alliance with the Other Side's Fringe Division, and helps them once they capture the mastermind behind the shapeshifters. Meanwhile, the Other Side's Elizabeth Bishop comes to see This Side's Walter Bishop to ask for his help.

Episode 10: Forced Perspective
The Fringe team discovers a girl who can see the future, and she warns that her vision always come true. Now, Olivia and the others must find the source of her newest vision, which shows a courthouse collapsing and killing hundreds of people.

Episode 11: Making Angels
While the Fringe Division on This Side deals with a murderer who uses a poison that can't possibly exist, Agents Farnsworth and Dunham from the Other Side come to pay the team a visit.

Episode 12: Welcome to Westfield
While investigating a plane crash near the small Vermont town of Westfield, Peter, Olivia, and Walter discover that they are trapped in the town and surrounded by people who are going insane.

Episode 13: A Better Human Being
Olivia and the team investigate a mental patient who heard voices that describes a real-life murder. While she conducts the investigation, Olivia begins to be overwhelmed by the memories of Peter's Olivia, and they must decide if they wish to give in and accept Olivia's new persona.

Episode 14: The End of All Things
As David Robert Jones tortures a captive Nina in an effort to activate Olivia's cortexiphan-enhanced abilities, the dying Observer visits Peter and Walter at their lab and Peter must merge minds with him to learn his secrets.

Episode 15: A Short Story About Love
While Olivia deals with the ramifications of the memories of Peter's "Olivia" subsuming her, the Fringe team investigates the deaths of two couples and discovers that a twisted killer is trying to capture love in a bottle.

Episode 16: Nothing as It Seems
When a passenger on a Paris-to-New York flight transforms at the NY terminal and kills two TSA agents before dying himself, Peter realizes that the case is the same as one that he dealt with in the original timeline four years earlier. Meanwhile, Olivia is put on leave when Broyles discovers that 40% of her memories as an agent for him are now missing.

Episode 17: Everything In Its Right Place
Feeling left out on This Side, Lincoln travels to the Other Side to help Fringe Division investigate a vigilante who genetically damages his victims as he kills them.

Episode 18: The Consultant
When three men die under mysterious circumstances on This Side, Walter travels to the Other Side to determine how the same three men died over there and what the connection is.

Episode 19: Letters of Transit
In the year 2036, the Observers have conquered mankind and taken the planet for themselves. Only two brave Fringe agents stand between the Observers and the total subservience of Man... but to triumph, they'll need the help of a legendary figure from the past.

Episode 20: Worlds Apart
Walter realizes what David Robert Jones' end game is, and how it involves the cortexiphan subjects. The two Fringe teams work together to stop the pending crisis and realize that one world will have to make a sacrifice to stop Jones.

Episode 21: Brave New World (1)
While dealing with multiple cases of spontaneous combustion, Walter realizes who is responsible for Jones' plan and sets out to get proof. Meanwhile, Jones launches a series of new attacks after the bridge is shut down, in his bid to create a new universe for himself and his superior.

Episode 22: Brave New World (2)
In the climactic conclusion of the 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.

Source
contributed by codebreaker

waterlilybarb

Episode 1: Transilience Thought Unifier Model-11
In the year 2036, Peter, Astrid, Walter, and Peter's daughter Etta seek out to find Olivia, who holds the secret to uncovering the master plan that will allow the rebel fights to defeat the occupying Observer force.

Episode 2: In Absentia
After Walter's memories of the plan to defeat the Observers is destroyed, the team goes to his old Harvard lab to uncover a vital clue to stop the invasion.

Episode 3: The Recordist
To find a mineral necessary for their plans, the Fringe team travels into the wilds of Pennsylvania and finds an encampment made up of people who are recording human history since the invasion.

Episode 4: The Bullet That Saved The World
The team attempt to recover part of Walter's plan from a subway station and discover that an old friend is risking his life to help them... or is he?

Episode 5: An Origin Story
When the team learns of a way to cut off the Observers from their future, Peter interrogates an Observer prisoner while Olivia tries to come to grips with their daughter's death.

Episode 6: Through the Looking Glass and What Walter Found There
Walter discovers that one of his tapes holds the key to defeating the Observers. To obtain it, he must travel to an abandoned apartment building where time and space are compressed. Peter, Olivia, and Astrid follow, and Peter discovers that he may be able to fight the Observers directly.

Episode 7: Five-Twenty-Ten
Peter brings his new powers to bear as he plots out a way to destroy the Observers. Meanwhile, the team meets with Nina and Walter realizes he may be losing the struggle against his old self.

Episode 8: The Human Kind
Olivia goes to pick up another piece of equipment for Walter's plan and encounters a woman who informs Olivia that her coming was foretold. Meanwhile, Peter continues to use his Observer implant to plot Windmark's demise.

Episode 9: Black Blotter
Walter takes LSD in an attempt to learn more of the plan he created to defeat the Observers. Meanwhile, Olivia and Peter trace a mysterious signal and find Walter's secret weapon.

Episode 10: Anomaly XB-6783746
The Fringe team turns to Nina for help after finding the child Observer, Michael. However, to help her friends, Nina is forced to risk her cover at the Ministry of Science.

Episode 11: The Boy Must Live
Using the sensory deprivation tank, Walter learns of Donald's address and the team goes to see the former Observer known as September. Donald tells them of the plan and of the young Observer Michael's role in it.

Episode 12: Liberty
To rescue Michael, Olivia must travel to the Other Side and meet with old friends so that she can enter the lab and save the boy before he is dissected. Meanwhile, Windmark tries to determine exactly what danger Michael poses to the Observers.

Episode 13: An Enemy of Fate [SERIES FINALE]
To save the present, the Fringe team must send Michael into the future and stop the Observers from ever being created. To succeed, a father must sacrifice everything.

Source
contributed by codebreaker