When an international flight lands at Boston's Logan Airport and there are no signs of life, FBI Special Agent Olivia Dunham, a scientist, Walter Bishop, and his son Peter uncover a deadly mystery involving a series of unbelievable events. 

The link between a wildly accelerated pregnancy and a baby who ages in a matter of minutes is investigated; Peter endures his new role as his father's keeper; Olivia turns to Massive Dynamic's chief operating officer for assistance. 

The team investigates a bus full of dead commuters who appear to be fossilized, and uncover a man who has visions of pattern-related disturbances before they happen; Dr. Bishop requests a piano in the lab to help him process data. 

Broyles asks the team to investigate a deadly explosion at a New York construction site; after Olivia uncovers a commonality between disturbing events, Dr. Bishop takes matters into his own hands. 

The team investigates a man who has the ability to harness electricity; Olivia is shocked by a blast from her past; Dr. Bishop uses homing pigeons to help him crack the case. 

The trio investigate when a woman reappears, having been missing for weeks, with the ability to dish out death at the touch of a fingertip. 

When a strange parasite attaches itself to the internal organs of a dying FBI agent, Olivia suspects a connection to the Pattern; Peter and Walter tap into a dead man's brain waves. 

Walter's former bunkmate at the mental institute is linked to the abduction of a young musical prodigy by a serial kidnapper. Peter is concerned when Walter insists on going back to the mental institute to solve the case. 

A Massive Dynamic employee leaps to his death after hallucinating a butterfly attack. Agent Scott proves useful in investigating the case, but a frustrated Olivia wants to remove him from her consciousness once and for all. 

The team are called in to investigate a bank robbery when one of the thieves is found embedded in a solid wall. Walter believes they're after something of his, but things take a turn for the worse when the thieves ambush one of them. 

The FBI and an increasingly desperate Peter search for the abducted Olivia - unaware that the man heading the investigation is the one responsible for her disappearance. 

Olivia, Peter and Walter investigate the death of a car salesman who was found in a pool of goo; Olivia is upset when the case puts a loved one in harm's way. 

The team finds freakish remains at the crash site of an international jumbo jet; with answers just out of reach, Olivia and Peter decide to go under cover. 

Unfazed by the unusual, Olivia, Peter and Dr Bishop investigate when a deadly toxin is unleashed, leaving its victims faceless. Grisly and gross in equal measure. 

A mysterious child who was living alone underground forms an unspoken bond with Olivia; a serial killer resurfaces. 

FBI agents Olivia Dunham and Peter Bishop are faced with a rapidly spreading unexplained phenomenon of the threatening kind. In an attempt to stop the spread, they enlist the assistance of Bishop's estranged father, the institutionalised scientist Dr Walter Bishop. 

Olivia Dunham dreams of a suicide incident at New York Grand Central Station. As the violent visions continue, a can of wonderfully weird worms is opened. Meanwhile, shocking details emerge about the ZFT manuscript. 

There is somebody killing people, and then draining the fluid from the spinal chords of the corpses. The deaths occur more and more frequently as Olivia, Peter and Walter go to great lengths to prevent them. 

Olivia starts having elaborate visions; Walter confesses his previous knowledge about the Z.F.T. manifesto; Peter's secret project is exposed. 

A person who is allied with the Fringe Division is attacked, and David Robert Jones emerges from hiding as a result. Walter is followed by the unknown observer.