Called in to help investigate a horrific incident on board an airliner, FBI agent Olivia Dunham turns to a mentally disturbed fringe scientist and his estranged son to help save her friend, who is afflicted with the same thing that killed the plane's passengers.
Olivia discovers a connection to an unsolved serial murder case when a woman dies giving birth to a child that grows from conception to old age in a matter of hours.
After a bus full of people are killed by being frozen in a crystalline material, Dunham's team is led to a mentally afflicted man who is drawing terrible events before they happen.
Following an underground explosion at a New York construction site, a cylindrical artifact turns up for Dr. Bishop to study. Olivia discovers the presence of an "observer" at Pattern-related incidents.
The team tracks a simple man with the ability to harness electricity, inadvertently causing horrific accidents when he is distressed. Olivia is confronted by a ghost from the past.
A missing woman with a rare disease reappears in a diner, leading to the deaths of everyone there by extreme radiation exposure. Olivia's team links the incident to illegal drug trials involving humans.
After an FBI agent falls ill, surgeons discover an unnatural parasite that has latched on to his heart. Olivia travels to Germany to try and meet with a prisoner who knows how to save him, while Peter and Walter try and talk to a dead man.
After a woman uses hypnotic lights to kidnap a brilliant young boy, Walter must return to the asylum where he lost 17 years of his life to talk with the only man who can help the team find him.
After an employee of Massive Dynamic falls to his death after being attacked by a swarm of butterflies, Olivia returns to the sensory deprivation tank to find a lead from John Scott's memories.
Olivia escapes her captors and tries to lead a team back to the facility where she was being held, only to be taken into custody by an F.B.I. agent who is investigating her. Meanwhile, her sister and niece arrive for a visit.
The team hunts for a serial killer who is using a highly advanced computer program to kill his enemies through their computer screens. A woman from Walter's past asks Peter if she can see him.
When a toxin kills a newsstand operator by sealing all his orifices, the team suspects the involvement of escaped German prisoner David Robert Jones. But they are stunned when the man walks right into F.B.I. headquarters with a challenge for Olivia.
When a mute child with extrasensory abilities is found living inside an abandoned building, Olivia believes he may be able to help them find a serial killer nicknamed "the Artist."
College animal rights activists free a genetically-engineered beast, which leaves its larvae in the bodies of those it attacks -- putting Charlie's life on the line.
Olivia finds that she is psychically connected to a murderer, a "reverse empath" whose self-hatred spills over onto his victims and causes them to kill or commit suicide.
As the F.B.I. launches a probe of William Bell, Olivia investigates a woman who appeared to spontaneously combust in the street. Meanwhile, Olivia experiences visions of what seem to be an alternate reality.
An attack on Nina Sharpe leads Olivia to Mr. Jones, who is trying to open a hole to another reality. Meanwhile, Peter goes in search of his father, who has gone missing.
