The 4400 Season One

Pilot
An unusual comet leaves behind 4,400 people who have disappeared over the last fifty years. While authorities are investigating, some of the 4,400 are behaving strangely. Everyone on Earth is excited about a comet passing by, but its trajectory changes to a collision course causing widespread panic. The comet turns out to be a giant ball of light which leaves behind 4400 people. They have all been missing from anywhere between a few months to 60 years. They haven't aged at all, and have no memory of what happened. "The 4400," as they come to call them, are put in quarantine and eventually released. Some of the returnees begin to exhibit strange and uncontrollable new abilities. Tom Baldwin and Diana Skouris, two Homeland Security agents, are appointed to find out what happened to the 4400.
The New and Improved Carl Morrissey
Another one of The 4400 begins to show strange behavior. Carl Morrissey suddenly shows immense strength and the urge to remove criminals from Bradley Park to bring it back to its old state. Carl Morrissey is a lowly supermarket employee who happens to be one of The 4400. He uses his new found powers - enhanced reflexes and strength - to become a vigilante and fight crime in his neighborhood. Lily is thrown in jail for violating the restraining order while looking in on her daughter and ex-husband's new life. Richard and Lily's romance begins to become more serious.
Becoming
Baldwin and Skouris deal with returnee Oliver Knox, involved in a series of murders. Jordan Collier, hotel magnate, puts himself in front as 4400 spokesman. Tom and Diana are sent out to investigate a homicide that resembles the MO of a serial killer who was never caught nor heard of for 21 years. The first suspect is Oliver Knox, a member of the 4400. However, Knox has an alibi for the night of the murder and another man confesses to all the crimes. Tom and Diana suspect that Knox is luring people to kill for him and try to lay a trap on him. Meanwhile, people begin to turn hostile toward the 4400, and Jordan Collier decides to organize his fellow returnees. But Richard feels uneasy about Collier's interest in them.

Trial by Fire
Someone has leaked a list of the current locations of all 4400's. When several of the returnees are bombed, Baldwin and Skouris must find out who did it. The 4400 are attacked by a series of bombings after Barbara Yates makes their names and addresses known to the public. Tom, Diana, and Dennis try to put an end to the bombings at the same time Tom is coping with Kyle's erratic behavior. Warren Lytell, an agent from Washington is sent to "monitor" the teams progress on The 4400 investigations. Jordan Collier offers protection to The 4400, while Richard and Lily begin to question his motives.
White Light
Baldwin's son Kyle has been kidnapped by agent Lytell for interrogation. Just when Tom and Diana are making plans to take him back, Maia has a premonition about Kyle being the answer to everything. Tom is furious upon finding out that Lyttel took his son Kyle into custody. Diana offers him help in getting Kyle back. Meanwhile, Richard suspects that Collier is trying to take control of Lily's life, and as soon as Collier reveals his intentions, Richard and Lily leave Arcadia Estates. Elsewhere, Danny snaps at Shawn when he finds out that he and Nikki have slept together. Tom and Diana finally find out what really happened to the 4400, which leaves a disturbing question: is this the end - or just the beginning?