Season 4 Episode 13:Great Leap Forward(2007)
As Seattle decends into chaos, the NTAC are forced to seek help from the Promise City, while Kyle's life is put in serious danger. Last in series, starring Joel Gretsch and Jacqueline McKenzie
Season 4 Episode 12:Tiny Machines(2007)
Meghan and Diana carry out the dangerous procedure of removing the entity from Tom, and Jordan is betrayed by a close friend. Meanwhile, Shawn is given help in his effort to rescue Kevin from Promise City
Season 4 Episode 11:Ghost in the Machine(2007)
Tom and Diana race to find the source of a virus that threatens Ubient Software, but the company's link to Drew Imroth, a suspected member of the Marked leads them to wonder if the attack is the work of an insider. Maia visits Promise City, where she receives an unexpected birthday present in the form of a visit from her biological parents. Drama, starring Joel Grestch and Jacqueline McKenzie, with Tim Dekay and Conchita Campbell
Season 4 Episode 10:One of Us(2007)
Jordan Collier's movements are threatened by Shawn who is developing a test that could tell people's reactions to a shot of promicin. Tom has trouble focusing on the hunt for the Tylers when he is plagued by dreams of the future, while Richard is visited by his wife who has been dead for over a year. Joel Gretsch stars
Season 4 Episode 9:Daddy's Little Girl(2007)
Richard decides to kidnap Isabelle from Jordan Collier's Promise City in the hope of having a fresh start, while Shawn's assistance is required when Tess takes over a diner. Drama, starring Joel Gretsch and Billy Campbell
Season 4 Episode 8:No Exit(2007)
Tom and Diana, along with other members of the NTAC, wake up trapped in the headquarters suffering with memory loss. Together the group form some unexpected alliances as they attempt to solve the mystery of how they got there
Season 4 Episode 7:Till We Have Built Jerusalem(2007)
Jordan Collier is targeted by assassins after his movement begins to gain momentum, and Shawn's efforts to run for a place in public office get him into trouble. Meanwhile, Diana begins to panic when she realises Maia has gone missing
Season 4 Episode 6:The Marked(2007)
A film-making conspiracy theorist goes on the run when he uncovers a potentially devastating plot, and Tom and Diana decide to pursue him. Meanwhile, Collier attempts to convince Shawn to join his movement
Season 4 Episode 5:Try the Pie(2007)
Tom finds Jordan living in a small town populated by faithful followers, and during his visit he talks to a woman who has the power to relieve stress through conversation. Meanwhile, Maia's visions of the future begin to give her nightmares, and Marco and Diana enjoy a nice discussion
Season 4 Episode 4:The Truth and Nothing but the Truth(2007)
Diana finds her sister April but discovers her sibling's life is at risk from the drug promicin, and Shawn is approached to run for office. Sci-fi drama, starring Joel Gretsch and Jacqueline McKenzie
Season 4 Episode 3:Audrey Parker's Come and Gone(2007)
Following her own murder, Audrey Parker uses her new ability of astral projection in an effort to lead Tom and Diana to her killer. Shawn decides to use his healing powers against the government's wishes, and Ben and Maia make a return to Seattle
Season 4 Episode 2:Fear Itself(2007)
Danny asks for Shawn's assistance in his attempt to find a shot of promicin, while Tom and Diana hunt for a person who is capable of turning people's phobias into reality. Meanwhile, Kyle receives news from Cassie which leads him to a book containing a prophecy involving Jordan Collier
Season 4 Episode 1:The Wrath of Graham(2007)
New series. A high-school student develops a unique ability after taking promicin, and Diana attempts to look for her sister who also took the enhancement drug. Meanwhile, the NTAC must deal with a new director, and Tom pays a visit to Isabelle in prison
Season 3 Episode 13:Fifty Fifty(2006)
Collier's vision of the future becomes a reality when he broadcasts an Internet presentation of his powerful drug. Tom and Diana race to thwart his masterplan - but Isabelle isn't far behind. Last in series, starring Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 12:Terrible Swift Sword(2006)
Tom and Diana suspect Jordan Collier is involved in the escape of a number of Nova group prisoners, who were freed from the NTAC by a figure with the ability to send people to sleep. Shawn is keen to thwart Collier's plans, until an alarming revelation convinces him to help the mysterious tycoon. Eerie drama, starring Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 11:The Gospel According to Collier(2006)
Tom and Diana embark on a manhunt that could reveal vital information about the future, after Shawn and Isabelle's wedding day is interrupted by a face from the past. Elsewhere, Kyle gets a surprising visitor at the prison who may be the key to his freedom. Drama, starring Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 10:The Starzl Mutation(2006)
Tom and Diana's investigation into a string of grisly murders leads them to uncover a sinister conspiracy in the government, while a returnee rewards Shawn with the power to see his own future. Eerie drama, starring Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 9:The Ballad of Kevin and Tess(2006)
Genius scientist Kevin Burkhoff is forced to take drastic action when his research into promicin, which holds the key to the secret of the 4400's powers, is discovered and his life is put in danger. Meanwhile, Shawn comes to the rescue of his rock-star idol. Sci-fi drama, guest starring Jeffrey Combs and Summer Glau, with Patrick Flueger
Season 3 Episode 8:Blink(2006)
Tom and Diana are put through an unusual experience when someone drugs them with a hallucinogen which causes them to come face to face with the people in their lives with whom they have unresolved issues. Meanwhile, Isabelle decides that she and Shawn should get married. Sci-fi drama, with Joel Gretsch and Megalyn Echikunwoke
Season 3 Episode 7:The Home Front(2006)
Tom and Diana continue to pursue elusive Nova group member Garry Navarro. As he once again manages to evade them, the agents begin to suspect he is being helped by Alana. Sci-fi drama, with Joel Gretsch and Sharif Atkins
Season 3 Episode 6:Graduation Day(2006)
Tom is plagued by nightmarish visions where Isabelle is responsible for the murder of billions of people - just as she begins a killing spree in revenge for the Nova Group's attack on Shawn. Meanwhile, Alana discovers the identity of the man responsible for the death of her family, and sets out to confront him. Sci-fi drama, with Joel Gretsch and Megalyn Echikunwoke
Season 3 Episode 5:Gone : Part Two(2006)
Part two of two. Realising he is important to the plans of those from the future, Tom resorts to drastic measures in an attempts to save Diana and get the children back - but his plan comes with an unexpected cost when he finds he must perform a task for the time-travelling agents. Meanwhile, the Nova group finally take their revenge on Shawn
Season 3 Episode 4:Gone : Part One(2006)
Part one of two. Tom and Diana race against time when they discover that someone has abducted several of the 4400 children. Meanwhile, Shawn's past catches up with him when he is attacked by the Nova Group. Sci-fi drama, guest starring Alice Krige with Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 3:Being Tom Baldwin(2006)
When Tom is accused of the murder of TJ Kim, an event of which he has no recollection, and witnesses place him at the scene, he goes on the run to clear his name with Diana in pursuit. Meanwhile, Shawn and Isabelle begin to grow closer. Sci-fi drama, with Joel Gretsch and Jacqueline McKenzie
Season 3 Episode 1:The New World(2006)
As the new series kicks off, Isabelle's return as a grown woman is one of two shocks for Richard, as Lily ages decades overnight - causing massive deterioration in her health. When Diana and Tom help tackle the radical 4400 Nova Group - who plan to openly demonstrate their gifts to the world - they are surprised to discover Gary's involvement with the activists, with Shawn as an unwitting financial backer. Mahershalalhashbaz Ali and Laura Allen star
Season 2 Episode 13:Mommy's Bosses(2005)
Tom and Diana race to find a cure for the mystery illness spreading among the returnees, who are beginning to drop like flies. They find the NTAC's executives are more interested in keeping the covert operation that caused the disease under wraps than looking for a solution. Meanwhile, Kyle contemplates turning himself in. Last in series
Season 2 Episode 12:The Fifth Page(2005)
Tom and Diana investigate when a large number of returnees from all around the globe start developing a strange illness. Dennis Ryler goes back to NTAC and issues the order to quarantine all of the 4400 - even those who are unaffected by the epidemic. The two agents then discover the virus could be part of a government conspiracy
Season 2 Episode 11:Lockdown(2005)
Diana brings a sick Maia into NTAC, only to discover one of the errant 4400 has chosen to mark Jordan Collier's birthday by unleashing a 'rage' bomb, making all males excessively aggressive - resulting in Tom pulling a gun on a colleague. Kyle returns to college where a romance blossoms, Lily grows sceptical about the Centre's interest in Isabelle, and Shawn tries to improve the faculty's image in the public eye
Season 2 Episode 10:Hidden(2005)
The NTAC team continue to follow the clues in their attempt to ascertain who killed Jordan Collier. However, as Tom gets more and more embroiled in the case he is thrust into an unenviable predicament, and is forced to make an important decision about where his loyalties lie. Meanwhile, Danny gets on the wrong side of Liv and Shawn
Season 2 Episode 9:Rebirth(2005)
Tom and Diana investigate a returnee with the curious ability to cure development defects in babies still inside the womb
Season 2 Episode 8:Carrier(2005)
Tom and Diana investigate when an entire community is wiped out by a lethal epidemic. It seems as though a returnee is deliberately spreading the disease and they race to discover the culprit before it causes havoc on a global scale. A government official joins the 4400 centre to add political influence to the institution's cause, and April uses Maia's psychic insight to win at gambling
Season 2 Episode 7:Life Interrupted(2005)
Tom Baldwin awakens to find himself in a new world where the 4400 mystery doesn't exist and his life is better than before. He faces the dilemma of whether to stay or return to the others, who are in desperate need of his help
Season 2 Episode 6:As Fate Would Have It(2005)
Maia has an eerie premonition in which she foresees the death of Jordan Collier - sending the team on a desperate mission to find an unknown killer. Tom finds his personal life disrupted by Kyle's sudden blackouts, and Lily's two families collide
Season 2 Episode 5:Suffer the Children(2005)
A teacher uses her supernatural ability to show her pupils how to hone their artistic talents - but their parents grow concerned about the application of such unconventional methods. Meanwhile, Richard and Lily have a run-in with the police, and Jordan warns Shawn about the dangers of exploiting his extraordinary powers
Season 2 Episode 4:Weight of the World(2005)
One of the returnees researches and masters a method of increasing body metabolism which, if made available as a commercial practice, would allow people to lose body fat instantly - but first they must investigate whether this would be a viable solution to obesity
Season 2 Episode 3:Voices Carry(2005)
A former baseball player reveals he is telepathically receiving the unspoken thoughts of everyone around him. He seeks help from the NTAC, although the organisation's magnates are only interested in using his extra-sensory powers to discover more about Jordan Collier's 4400 Centre
Season 2 Episode 2:Wake-Up Call - Part Two(2005)
Part two of two. Drama about two FBI agents investigating the mysterious reappearance of 4,400 missing persons. Public opinion is divided between those who embrace the returnees and those who fear them. However, as they struggle to rebuild their lives, it becomes clear each will play a pivotal role in events still to come. Joel Gretsch and Jacqueline McKenzie star
Season 2 Episode 1:Wake-Up Call - Part One(2005)
Part one of two. Drama about two FBI agents investigating the mysterious reappearance of 4,400 missing persons. Public opinion is divided between those who embrace the returnees and those who fear them. However, as they struggle to rebuild their lives, it becomes clear each will play a pivotal role in events still to come. Joel Gretsch and Jacqueline McKenzie star
Season 1 Episode 6:White Light(2004)
Tom and Diana finally learn the truth about the returnees, but their discovery causes them to realise the saga could be set to continue. Last in series
Season 1 Episode 5:Trial By Fire(2004)
A journalist looks to make a scandal out of the mysterious reappearance of the 4,400 returnees and publicises their names and addresses - a situation which gives rise to a series of life-threatening firebombings
Season 1 Episode 4:Becoming(2004)
Tom and Diana investigate a murder that bears a striking resemblance to crimes committed by a serial killer 25 years previously. The first suspect is Oliver Knox, a member of the 4400 - but he has an alibi for the night of the murder and another man later confesses to all the crimes
Season 1 Episode 3:The New and Improved Carl Morrissey(2004)
One of the 4400 returned abductees uses his new found powers to become a vigilante and fight crime in his neighbourhood - a decision that proves fatal. Meanwhile, Lily is thrown in jail for violating the restraining order while looking in on her daughter and ex-husband's new life
Season 1 Episode 2:Pilot - Part Two(2004)
Conclusion. The returnees come to realise the world has moved on without them and that living a normal life is now an impossible dream. Agents Baldwin and Skouris discover some of them have begun to exhibit mysterious abilities
Season 1 Episode 1:Pilot(2004)
Pilot episode of the sci-fi series. FBI agents Tom Baldwin and Diana Skouris are assigned to investigate the sudden reappearance of 4,400 people who mysteriously vanished at some point during the previous 50 years, hoping to explain how and where they went, as well as discovering why they are still the same age, and have no sense of lost time