Fringe Season 4 Episode Guide
Season 4 has 22 episodes, from September 23, 2011 to May 11, 2012. Descriptions stay brief and spoiler-light.
Episode 1: Neither Here Nor There
Airdate: September 23, 2011
Description: 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.
Episode 2: One Night in October
Airdate: September 30, 2011
Description: As the victims of a highly intelligent serial killer stack up in the Alternate Universe, the Fringe Division "over here" is asked to assist.
Episode 3: Alone in the World
Airdate: October 7, 2011
Description: The Fringe team investigates when the bodies of two 12-year-olds are found in an advanced state of decomposition just hours after they were last seen bullying another boy.
Episode 4: Subject 9
Airdate: October 14, 2011
Description: Olivia uncovers a dangerous force that may be connected to Walter's past experiments with the drug Cortexiphan.
Episode 5: Novation
Airdate: November 4, 2011
Description: As the threat of the translucent shapeshifters intensifies, former Massive Dynamic biochemical researcher Malcolm Truss enters the fold.
Episode 6: And Those We've Left Behind
Airdate: November 11, 2011
Description: Peter is still being held by Fringe Division who have yet to fully trust him, so when a pattern of tragic time loop anomalies emerges, the team begin to wonder if Peter's unexplained appearance is responsible.
Episode 7: Wallflower
Airdate: November 18, 2011
Description: While Olivia struggles with migraines, Fringe Division investigate an invisible force which kills its victims and causes the body to turn a ghostly white.
Episode 8: Back to Where You've Never Been
Airdate: January 13, 2012
Description: In an effort to find a way home, Peter journeys to the Alternate Universe to confront Walternate.
Episode 9: Enemy of My Enemy
Airdate: January 20, 2012
Description: Peter and Lincoln'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.
Episode 10: Forced Perspective
Airdate: January 27, 2012
Description: 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.
Episode 11: Making Angels
Airdate: February 3, 2012
Description: 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.
Episode 12: Welcome to Westfield
Airdate: February 10, 2012
Description: 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.
Episode 13: A Better Human Being
Airdate: February 17, 2012
Description: 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.
Episode 14: The End of All Things
Airdate: February 24, 2012
Description: As David Robert Jones uses a captive Nina in an effort to activate Olivia's Cortexiphan-enhanced abilities, a dying Observer appears in the lab and forces the Fringe team to take extraordinary measures in an attempt to stop…
Episode 15: A Short Story About Love
Airdate: March 23, 2012
Description: Fringe Division investigates a suspect who is using pheromones to replicate love…
Episode 16: Nothing as It Seems
Airdate: March 30, 2012
Description: Olivia, having willingly accepted the replacement of her memories with those from Peter's timeline, is put under psychiatric evaluation and Lincoln Lee is put in charge of the team in her absence.
Episode 17: Everything in Its Right Place
Airdate: April 6, 2012
Description: Heading over to the Alternate Universe, Agent Lincoln Lee and the other Fringe Division track a vigilante who is leaving mutilated corpses in his wake, only to discover a hidden connection to the shapeshifters both universes have been…
Episode 18: The Consultant
Airdate: April 13, 2012
Description: Walter travels to the Alternate Universe to assist in the investigation of a Fringe event with ties to both worlds.
Episode 19: Letters of Transit
Airdate: April 20, 2012
Description: The Observers, no longer content with observing history, return to the past and stage an invasion of 2015, transforming human society in a totalitarian state under their control.
Episode 20: Worlds Apart
Airdate: April 27, 2012
Description: When multiple earthquakes strike simultaneously across the globe in both universes, the Fringe teams on both sides unite in their quest to defeat a common foe.
Episode 21: Brave New World: Part 1
Airdate: May 4, 2012
Description: When a mysterious Fringe event suddenly causes people to spontaneously combust, Walter is forced to revisit his painful past while Fringe Division faces off against David Robert Jones to save the world, or worlds.
Episode 22: Brave New World: Part 2
Airdate: May 11, 2012
Description: Pushed to breaking point, Fringe Division desperately attempts to prevent a catastrophic event orchestrated by David Robert Jones and his hidden associate, Dr.