Season Four Episode Guide

Neither Here Nor There

Episode #: 401
Air Date: 09.23.11
Our Rating:

While the two universes initiate an uneasy alliance, Olivia partners with Lincoln Lee to search for a serial killer with translucent skin. Peter's absence from the new timeline has repercussions for those who depended on him.

One Night in October

Episode #: 402
Air Date: 09.30.11
Our Rating:

After a serial killer strikes in the parallel universe, the alternate team asks for Olivia's help recruiting the suspect's double from our world -- where he is a forensic psychologist specializing in serial killers.

Alone In the World

Episode #: 403
Air Date: 10.07.11
Our Rating:

The death and rapid decomposition of two school bullies leads the team to a dangerous entity and the 12-year-old boy who seems to have a connection with it. Meanwhile, Walter is increasingly troubled by his hallucinations.

Subject 9

Episode #: 404
Air Date: 10.14.11
Our Rating:

Walter tries to help Olivia identify an energy apparition that is targeting her, leading them to a man who was once a part of the Cortexiphan experiments. Meanwhile, Walter learns that Olivia is about to decide whether or not to have him recommitted to St. Clare's.


Episode #: 405
Air Date: 11.04.11
Our Rating:

When an advanced shape-shifter goes after a scientist it believes can stabilize its cellular structure, Peter takes advantage of the situation to prove his usefulness -- and to ask Walter for help understanding why he is there.

And Those We've Left Behind

Episode #: 406
Air Date: 11.11.11
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The team suspects that Peter's presence may be to blame for a sequence of spherical time distortions, but the investigation leads to a brilliant theoretical physicist and her desperate husband.


Episode #: 407
Air Date: 11.18.11
Our Rating:

After an attack by an invisible assailant leaves the victim a ghostly white, the Fringe team discovers a man with a unique genetic disorder who may have found a way to make himself visible.

Back to Where You've Never Been

Episode #: 408
Air Date: 01.13.12
Our Rating:

Peter and Lincoln visit the other universe, where Lincoln wants to uncover the new shape-shifters' agenda and Peter hopes to find a way home with help from Walternate. But the mission goes very wrong when their real identities are discovered.

Enemy of My Enemy

Episode #: 409
Air Date: 01.20.12
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The other universe comes face-to-face with Robert David Jones, who uses his inside connections to acquire intel for a more long-term plan.

Forced Perspective

Episode #: 410
Air Date: 01.27.12
Our Rating:

The Fringe team searches for a young artist with the ability to see death before it happens, which becomes even more crucial after she predicts a mass-casualty event. Meanwhile, Olivia is preoccupied by her own personal warning from one of the Observers.

Making Angels

Episode #: 411
Air Date: 02.03.12
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Olivia and Peter search for a man who can predict people's deaths, and is killing them to spare further pain and misery. The other Astrid shows up in Walter's lab with a very personal mission.

Welcome to Westfield

Episode #: 412
Air Date: 02.10.12
Our Rating:

Peter, Walter, and Olivia find themselves trapped in a small Vermont town where residents appear to be afflicted by severe schizophrenia with supernatural origins. Meanwhile, Olivia herself experiences memories of her alternate history with Peter.

A Better Human Being

Episode #: 413
Air Date: 02.17.12
Our Rating:

After a mental patient appears to witness a murder without being present at the crime scene, Olivia and Peter suspect that he has a telepathic connection to the killers. Walter grows suspicious that Massive Dynamic may have reverse-engineered Cortexiphan.

The End of All Things

Episode #: 414
Air Date: 02.24.12
Our Rating:

As David Robert Jones tortures Nina in order to activate Olivia's abilities, Peter realizes that the only way to find her is to enter the mind of the rogue Observer called "September."

A Short Story About Love

Episode #: 415
Air Date: 03.23.12
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A murderer targets couples in love, extracting concentrated pheromones from the men in order to create a personal moment with their significant others. Meanwhile, Peter discovers that the Observer left him a hidden message.

Nothing As It Seems

Episode #: 416
Air Date: 03.30.12
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After an airline passenger transforms into a massive creature, Peter recognizes the case as one from his timeline -- but now events are unfolding differently. Olivia defies FBI orders after she is taken off active duty.

Everything In Its Right Place

Episode #: 417
Air Date: 04.06.12
Our Rating:

Lincoln takes a trip to the other side and finds himself drawn into a case with the other Fringe Division, chasing a very unusual shape-shifter in the hope of finding David Robert Jones.

The Consultant

Episode #: 418
Air Date: 04.13.12
Our Rating:

The mysterious deaths of three people turn out to be connected to a plane crash that killed their doppelgangers on the other side, sending Walter over to team with Lincoln and the other Olivia. Meanwhile, Olivia's investigation into the mole looks to be hopeless.

Letters of Transit

Episode #: 419
Air Date: 04.20.12
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In the year 2036 two Fringe agents may have finally found someone who can help them free the world from the dystopian rule of the Observers: Dr. Walter Bishop, frozen in amber for more than 20 years.

Worlds Apart

Episode #: 420
Air Date: 04.27.12
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With the realization that Jones is using former Cortexiphan test subjects in a plan to collapse the two universes, both sides must weigh the cost of shutting down the bridge that joins them together. Olivia reconnects with a man from her childhood.

Brave New World, Part 1

Episode #: 421
Air Date: 05.04.12
Our Rating:

After an attack using advanced nanites causes victims to spontaneously combust from the inside out, Olivia and Peter hunt for David Robert Jones -- but Walter suspects that an old friend may be the real culprit.

Brave New World, Part 2

Episode #: 422
Air Date: 05.11.12
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The team searches for Walter, who now stands with William Bell on the cusp of the birth of a brand new universe. The Observer September returns, and a former patient turns out to be more than she appears.