Writer: Frederick Rappaport, Director: Vincent Misiano
Back after 30 years, a teacher Heather Tobey has unearthed her ability as a muse to bring out virtuoso-level talent in art and music in certain students. Although seen as an amazing feat by most of the parents in the community, a small minority find her skill threatening - and a danger to their children. These malcontents bring up charges of child abuse against her to bar her from teaching, and one of the students poses a different kind of threat to Heather when she fails to find the light inside of him. Richard is caught off-guard when he is recognized as an "AWOL 4400" and arrested by a police officer, but in the end receives help from Jordan Collier; Shawn gets involved with a group of homeless teenage runaways; and Kyle's episodes of lost time become more frequent.

Writer: Scott Peters, Director: Oz Scott
After a 16-year absence, 4400 Trent Appelbaum returns to find his wife dead, leaving their daughter with financial burden. But Trent's luck soon takes a turn for the life changing when he discovers his ability to speed up weight-loss at an exponential rate. Now companies are practically knocking down his door, each willing to pay top dollar for the right to put Trent's ability on the open market, but Trent's ability turns deadly for thosewho sample it. Richard, Lily, and Isabelle find a respite from their life on the road at the home of a fellow 4400; at the 4400 Center, a celebrity pop star joins Collier's cause; and Kyle attends a frat party, and learns that too much fun can be dangerous.

Writer: Craig Sweeny, Ira Steven Behr, Director: Leslie Libman
One year after the events on Highland Beach revealed that the 4400 were taken and returned by future humans, the world is a much different place. NTAC agent Tom Baldwin has been at desk job for the past 12 months, penance for his acts of insubordination despite the fact that those acts unlocked the mystery of the 4400. Kyle, Tom's son, has been living under observation at NTAC, where he has endured numerous tests that have revealed no new information. Diana Skouris, Tom's old partner, appeals to Nina Jarvis, the new head of the Pacific Northwest Division of NTAC, to reinstate Tom in the field. Diana has also adopted Maia Rutledge as her daughter, unaware that the girl still has visions. Richard, Lily, and their baby Isabelle (now six months old) are living in a cabin, hiding from both Jordan Collier and NTAC. Collier has become the self-proclaimed figurehead of the 4400, and is opening the first "4400 Center," a place intended not only for fellow returnees but also for regular, everyday people who are looking to "unlock" the 4400 within themselves. And Shawn Farrell has left his family behind to become Collier's protege, using his healing ability to bring money contributors to the center. NTAC gets a call from Abenson Psychiatric Hospital, where Tess Doerner, a 4400 paranoid schizophrenic, seems to have taken some sort of mind control over the institution's orderlies and inmates. Upon his release from NTAC, Kyle is determined to rescue Shawn from Collier. And Richard and Lily are forced to flee their home when a religious zealot decides that baby Isabelle is the devil and must be destroyed.

Writer: Lisa Melamed, Director: Vincent Misiano
Gary Navarro, a minor league baseball player back after 30 years, finds that hearing everyone's thoughts is driving him to the edge of madness. When he seeks help from NTAC, the higher-ups are more interested in how he can unearth information about Jordan Collier than how they can assist Garry with getting his life back. As the case occupies most of his time, Tom finds himself struggling as a single father. Meanwhile, Kyle starts to get his life back through the prospect of a new relationship, Diana finds herself dealing with the unexpected arrival of her sister April, and as Richard, Lily, and Isabelle continue their life on the run, Richard grows increasingly disturbed by his daughter's apparent abilities.

Writer: Craig Sweeny, Director: Nick Gomez
NTAC goes on full alert when Maia informs Diana that she had a vision that Jordan Collier will be killed. As the agents rush to find the potential assassin, Tom's troubles continue to build at home, where an increasingly alarmed Kyle struggles to find the cause of his blackouts. Lily reunites with her daughter Heidi, but when Lily introduces Heidi to Isabelle, it becomes clear that the infant doesn't approve of her halfsister's entrance into their lives; Shawn brings one of the street kids, Liv, into the 4400 Center as a First Key, hoping to give her a new and better life off the streets; and NTAC issues a subpoena demanding Diana surrender Maia's diary of predictions.

Writer: Ira Steven Behr, Director: Michael Watkins
Tom Baldwin wakes up to find everything his world is different: he's has a new wife, his son Kyle is a medical student, and, most disturbing of all, no one has ever heard of the 4400. While he still remains an agent working at NTAC with Diana, nothing else in his world resembles the predicament he was in 24 hours ago. His solace comes in form of his spouse, Alana, who happens to be a 4400. It turns out this world is a creation by the futurists to serve as a sanctuary for Tom, with his new wife at the nexus of it all. Tom is faced with the decision of whether to stay in this perfect life or return to his old one, where an uncertain future is depending on him.

Written by Douglas Petrie, Directed by Leslie Libman
An entire town of dead people leads Tom and Diana on the trail of Jean DeLynn Baker, a 4400 who has the ability to grow toxin-emitting spores on her hands. It seems Jean has come to the conclusion that the lethality she now possesses is not a curse, but is instead a gift her to "purify humanity." Meanwhile, Matthew Ross joins the 4400 Center as an advisor to Shawn, who has become overwhelmed. The Center also finds Lily trying to keep Isabelle at peace while she adjusts to her introduction to her halfsister Heidi. Elsewhere, still unaware of his role in Jordan Collier's assassination, Kyle reconnects with Wendy; and Diana leaves Maia in the care of her sister, who crosses the line and uses Maia's pre-cognitive abilities for profit.

Written by Lisa Melamed , Directed by Milan Cheylov
Tom and Diana are caught in the middle of an international incident when Edwin Mayuya, a 4400 with the ability to repair damaged chromosomes in utero, is revealed to be a Rwandan war criminal. Despite the good Edwin has done, NTAC must weigh whether it is enough to absolve him of his crimes against humanity. Meanwhile, Richard attends a bittersweet reunion with his old Korean War buddies; Diana deals with her sister April's abuse of Maia's power; and Shawn tries to reconnect with his own family.

Written by Frederick Rappaport, Directed by Vincent Misiano
NTAC follows a series of clues which leading them to Jordan Collier's killer, and when Tom discovers Kyle was the murderer, he must choose between the law and his family. Meanwhile, at the 4400 Center, Danny stirs up a mess with Liv - as well as with his brother Shawn in the process.

Written and Directed by Douglas Petrie
On Jordan Collier's birthday, an unknown 4400 releases a "rage bomb" at NTAC, causing all the male agents to revert to their primal instincts. In order to stop the spread of the behavior, NTAC goes into lockdown, sealing all personnel inside. Now it's up to Diana to find a cure and stop the carnage before it's too late. Meanwhile, Lily suspects the 4400 Center may have nefarious motives toward Isabelle, Shawn adjusts to being the figurehead of the 4400 in the media spotlight, and Kyle finds the prospect of a new romantic relationship.

Written by Ira Steven Behr & Craig Sweeny, Directed by Scott Peters
When 4400s become ill with the same harsh and seemingly unfounded symptoms, NTAC issues a warrant to quarantine those afflicted. In an effort to avoid the confinement of the quarantine they were kept in when they first returned in August 2004, the 4400 Center establishes a safe house for its members. As the 4400s in hiding plot their next move, Agents Baldwin and Skouris race to find a cure for the infirmed - and discover a shocking secret in the process.

Written by Ira Steven Behr & Craig Sweeny, Directed by John Behring
On the heels of discovering that NTAC is behind the disease plaguing the 4400, Tom and Diana find themselves enveloped in a government conspiracy to hide the truth. Although the disease was an unforeseen side affect of an inhibitor secretly administered to the 4400 to prevent the emergence of special abilities, it's clear that the powers that be are more concerned with covering their tracks than curing the disease. Now Tom and Diana must face off against their own agency as they race against time to get to the bottom of NTAC's coverup and help find a cure before it's too late.