While Olivia fights to get back home, Peter and Walter try to move on with their lives, unwittingly alongside alt-Olivia. 

The team investigate a mystifying case where people are discovered in a trance-like state that ultimately leads to their death. The unlikely suspect: a mysterious box. 

Anomalous events lead the team to investigate a series of deadly incidents with unimaginable coincidences. Elsewhere, Bishop shares his plan of strategy with Col. Broyles. 

Newton is concerned about the ramifications of a distressing development involving a high-ranking official and is forced to call in a sleeping shapeshifter. Olivia is soon on high alert, and Walter finds himself in a perilous situation. 

`Over There', the team investigate when a twin frees his brother from a quarantined Amber area. Visions of Peter continue to haunt a home-sick Olivia too. 

Fifteen people along the Eastern seaboard suffer retrograde amnesia after listening to their shortwave radios on the same frequency; the anticipation of Olivia's return escalates. 

Colonel Broyles is hit hard when a serial kidnapper `Over There' strikes again. Meanwhile, Olivia needs Henry's help as her fight to return home rages on. 

Peter grapples with the aftermath of recent events and Olivia desperately searches for an ally. A device that communicates between the universes is discovered too. 

The Fringe Division investigate a series of mysterious, reanimating events. Meanwhile, Peter comes to terms with the reality of his relationship with Olivia. 

An Observer makes contact with the team to help rectify a mistake. Meanwhile, Walter befriends the keyboard player of his favourite 1970s band, `Violet Sedan Chair'. 

Walter worries about Peter after observing Massive Dynamic's assembly of the doomsday device; an intense investigation begins after a dead body is discovered. 

A scientist dies after ingesting a cloud of blue powder that disintegrates his bones; a person from Walter's past reluctantly agrees to help with the investigation. 

A terrorist "over there" arms himself with an insect that enjoys human flesh; alternate Olivia is reunited with her boyfriend; despite remaining determined to save his world, Walternate discovers there are lines he won't cross. 

This week's phenomenon leads the team to an elderly woman grieving over her husband's death. Peter and Olivia try to repair the emotional rift between them as well. 

A poignant period of time for both the Bishops and Olivia is revealed. 

The team investigates a group of thieves who are able to break the laws of gravity; Walter attempts to delay the damage he has caused. 

The team's latest case revolves around a woman who seems to possess the 'gift' of immortality. Elsewhere, William Bell continues to reside in Olivia's body. 

Heading 'Over There', events really do take a turn for the worse for Alt-Olivia. Meanwhile, when disturbing details come to light, concerns grow for Olivia. 

Back Over Here for a trippy season standout, the race is on to remove William Bell's consciousness from Olivia's body before she's lost forever. 

It seems to be the beginning of the end when Walternate figures out how to save 'Over There'. The repercussions, however, are immediately felt 'Over Here'. 

Olivia joins forces with Sam Weiss to stop the devastation from spreading. Weiss reveals a secret about his family and the incomplete collection of information. 

Prepare for a tangle of twists in this dizzying third season finale. Peter pursues a solution to the crisis threatening to negate everyone in existence.