[2][1] It was created and written by Scott Peters and René Echevarria, and it starred Joel Gretsch and Jacqueline McKenzie.

[3] In the series' pilot episode, a ball of light deposits a group of 4400 people in the Cascade Range foothills near Mount Rainier, Washington, in the United States.

[4] The National Threat Assessment Command (NTAC), a division of the Department of Homeland Security, is in charge of dealing with the return of the 4400.

More significantly, a small number of the returnees begin to manifest paranormal abilities, such as telekinesis, telepathy and precognition, as well as other "gifts".

For example, in the pilot, Shawn Farrell manifests an ability to heal the broken neck of a dead bird, bringing it back to life.

The first-season finale, "White Light", reveals that the 4400 were abducted not by aliens, but by humans from the Earth's future, that Kyle Baldwin was to be their "messenger", and that they were returned to avert a catastrophe.

Another faction, which prefers the status quo, opposes the 4400, and has sent their own operatives, including Isabelle Tyler and "the Marked", into the past.

Eventually, Jordan Collier, a returnee who declares himself the savior of humanity, makes promicin shots available to the general public.

Although the government outlaws promicin use, thousands of previously ordinary people have developed superhuman abilities, severely complicating NTAC's task.

Collier later annexes a part of Seattle and transforms it into "Promise City", a self-proclaimed paradise open to all people with superhuman abilities.

At the conclusion of the series, Danny Farell's uncontrolled ability exposed some of the residents of Seattle to promicin, resulting in about 9,000 deaths and as many newly empowered humans, while at the same time forcing the remains of NTAC (now themselves mostly promicin-positive) to ask Jordan Collier and his followers (as the only group immune to the 50% chance of death from exposure) to become the de facto government of Seattle.

In the series, promicin is a fictional neurotransmitter the human body produces that controls and regulates bodily functions.

[9] In the fourth season, Dr. Burkhoff claims to have discovered how promicin interacts with the body, thus being able to predict whether a person will survive the shot or not.

As discovered by Marco in the episode "The Starzl Mutation", Seattle Presbyterian Hospital started using a flawed radiation machine to treat their cancer patients in 1969.

[9] The 4400 is set in Seattle, Washington, United States,[11] but actually filmed in the Vancouver, British Columbia, Canada, area.

Billy Campbell, the actor who plays Collier, took most of the third season off to sail around the world, returning in the final four episodes.

[21] Production of the fourth and final season began in early 2007 for a mid-year premiere, returning with the episode "The Wrath of Graham".

[22] On September 14, 2000, Variety reported that American Zoetrope, an independent film production company owned by the family of filmmaker Francis Ford Coppola, had made two television production deals; one of them being made with Viacom to produce full-length television series, having themselves been in the television production industry before with miniseries and made-for-television films like Dark Angel and Moby Dick and already produced their first full-length series First Wave for Space in Canada and the Sci-Fi Channel in the United States.

The theme song of the show is "A Place in Time", written by Robert Phillips and Tim Paruskewitz and performed by Amanda Abizaid.

[3] The soundtrack to The 4400 was released on May 8, 2007, by Milan Records and includes music from the first three seasons, as follows: The last track does not appear in the series.

[42][43] In February 2019, it was reported that the project would roll over to the next development cycle to allow Elmore and Sweeny to finish the pilot script.

[46] In April 2021, Brittany Adebumola, Jaye Ladymore and Amarr Wooten joined the cast as series regulars.