Seattle falls into chaos and NTAC is forced to look to Promise City for help. Meanwhile, Isabelle is ordered to murder Kyle Baldwin and Jordan attempts to escape from The Marked.

Meghan and Diana discover a way to extract the future entity out of Tom, which could cost him his life. Meanwhile, Shawn recruits a small band of Promicin positives to bust Kevin out of Promise City. And Isabelle deliver...

A computer virus attacks Ubient Software, owned by Drew Imroth – a suspected member of the Marked. Elsewhere, Maia visits Promise City and receives an unexpected birthday gift.

Tom has trouble focusing on the hunt for Richard Tyler because of dreams he's been having about the future. Richard, in hiding with Isabelle, is visited by his wife, Lily, who has been dead for over a year. Meanwhile, Jo...

Richard surprises Isabelle when he shows up in Promise City ... but the happy reunion takes a turn when Richard kidnaps her in hopes of starting a new life with his daughter. Meanwhile, Tess, her schizophrenia out of con...

Opposing sides all wake up inside NTAC without any memory of how they got there. A lockdown at NTAC traps everyone, including Collier and his group, and everyone must put aside their differences and work together in orde...

Shawn Farrell's political ambitions are threatened by a woman who claims he healed her mother in return for sex. At the same time, Jordan Collier annexes part of Seattle itself and calls it "Promise City", threatening to...

Collier tries to persuade Shawn to join his movement. Meanwhile, a 4400 who knows the truth behind historic conspiracies goes missing, prompting a search by Tom and Diana.

Tom locates Jordan Collier, who is living in a small town. Meanwhile, Maia has a shocking vision of the future

Diana finds April, whose life is in danger because of promicin.

A woman can project herself astrally, remaining unseen, but her body is murdered during astral projection. She must find a way to contact Tom and Diana to catch her murderer.

Kyle receives a lead from Cassie, leading to a book containing a prophecy about Jordan Collier.

A new director takes over NTAC, while a high-school student develops an ability after taking promicin.

Jordan goes public about his "resurrection", and summons a 4400 with a tracking ability to find Kevin and Tess, who are still at large.

Tom and Diana discover that Jordan Collier has been spotted, and try to track him down. Kyle gets a surprising visitor in prison.

A former Army Ranger who was recruited for a secret government program contacts NTAC when an experiment giving him and others 4400 abilities goes wrong, causing one patient to go on a killing spree.

Kevin is on the run after horribly mutating due to the promicin experiments. Tom and Diana go to Tess for help. Diana gets what she believes is the flu and discovers something startling.

Exposure to a new 4400 ability causes Tom and Diana to have hallucinations of loved ones from their past. Isabelle decides she wants Shawn to marry her - no matter what.

Tom and Diana continue the hunt for terrorists, while Dennis Ryland finds one in an unlikely place. Nikki pays Shawn a visit.

After Shawn is attacked, Isabelle seeks revenge on the Nova Group. Tom hesitates to kill Isabelle.

Tom and Alana experience visions of Maia, whom they have no memories of. When Diana's life is put in danger, Tom makes a grim bargain to bring back the children.

Someone is targeting young 4400s and Maia gets kidnapped. Shawn receives a threat from the Nova Group.

Tom is charged with a crime he does not remember committing, and Shawn helps Isabelle through her growing pains.

Richard has to cope with two horrendous changes in his life after he discovers that Isabelle and Lily have both aged substantially. The Nova Group reveals itself as a group of 4400s who have the power to influence the wo...

Richard has to cope with two horrendous changes in his life after he discovers that Isabelle and Lily have both aged substantially. The Nova Group reveals itself as a group of 4400s who have the power to influence the wo...

4400s across the globe are developing strange, severe illnesses, leading Tom and Diana into the heart of a terrifying conspiracy.

NTAC goes into an emergency lockdown when a 4400 launches a terrorist attack.

NTAC and Tom enter a race against time as they both draw closer to Jordan Collier's assassin.

Tom and Diana investigate a 4400 with the ability to repair defects in fetuses.

A 4400 whose ability has turned her into a walking plague believes she is the next messiah.

Tom finds himself in a world where the 4400 abductions never happened.

A morbid premonition from Maia threatens the future of the 4400 Center.

Tom and Diana investigate a 4400 junior high school teacher accused of child abuse.

Tom and Diana investigate a 4400 whose ability to accelerate the human body's metabolism just may be the perfect weight loss drug.

A returnee exhibiting telepathic abilities seeks help from NTAC, but is instead used as a mole to infiltrate Jordan Collier's 4400 Center. Kyle prepares to enter into college but discovers his father has not paid his tui...

Tom and Diana investigate a mysterious structure which is being built at a psychiatric hospital, based on the drawings of a schizophrenic 4400, Tess Doerner. Richard must protect his family when he and Lily are discovere...

Tom and Diana investigate a mysterious structure which is being built at a psychiatric hospital, based on the drawings of a schizophrenic 4400, Tess Doerner. Richard must protect his family when he and Lily are discovere...

Tom and Diana break Kyle out of NTAC quarantine and head to Highland Beach. In a virtual reality with Kyle, Tom learns where the 4400 were taken, who took them, and why.

Several 4400s are killed during anti-4400 terrorist bombings, Tom and Diana must race to stop the perpetrators. Kyle begins to exhibit strange behaviour and begins understand what is wrong with him.

Tom and Diana are tasked with investigating Oliver Knox who is using his ability of suggestion to influence men to murder women. A list of 4400s is leaked to the public. Kyle awakens from his coma after Shawn uses his ab...

Tom and Diana investigate Carl Morrissey, a 4400, who is using his ability of enhanced reflexes and strength to fight crime single-handedly. Lily is arrested when she attempts to see her daughter. Diana takes Maia home w...

A comet's path changes course towards Earth when suddenly it comes in for a "landing". 4400 people, assumed to be dead or missing over the past 58 years, reappear and none have aged a day or have any memories since disap...