The 4400

Tom and Diana, with the help of Gary Navarro, try to track down T.J Kim, a 4400 whose ability they believe caused a man to stab Dennis Ryland. Richard and Lily are forced to deal with a now grown Isabelle.

Gary Navarro is arrested after attempting to assassinate Dennis Ryland. Isabelle attempts suicide in the hope of saving her mother, but fails when she survives a fall from the roof of the 4400 Center.

T.J. Kim is murdered, and Tom is accused of committing the murder. Shawn and Isabelle grow closer.

Tom and Diana search for someone who is kidnapping young 4400s. Shawn is threatened by the Nova Group.

While in one of Alana's fantasies, Tom and Alana see Maia, though they have no memory of her existence. Diana's life is threatened, and Tom brokers a deal with the future to set history straight.

Isabelle seeks revenge on the Nova Group after they attack Shawn. Alana confronts the man responsible for killing her husband and son in a car accident nine years ago.

With Dennis Ryland's help, NTAC tracks down the remaining members of the Nova Group. Nikki pays Shawn an unexpected visit.

Tom and Diana are drugged with a hallucinogen, which was created from an oil secreted from the hands of a 4400.

Kevin Burkhoff becomes a marked man when his research on promicin is discovered. Tom and Diana search for Kevin, but discover how far he will go to protect his work. Shawn meets his idol at the 4400 Center.

Tom and Diana's investigation into a series of gruesome murders leads them to uncover another conspiracy within the government. At the 4400 Center, Shawn receives a gift from another returnee that allows him to see his future.

NTAC and the 4400 Center work together to find Jordan Collier. Kyle Baldwin gets a surprising visitor at the state prison.

Nova Group members that were in the custody of NTAC escape from jail with outside help from Jordan Collier. Diana tells April about her relationship with Ben. Shawn and Richard learn that Isabelle is working with Dennis Ryland.

Tom and Diana continue their investigation on Jordan Collier's plan for mankind. Dennis Ryland returns to NTAC. Isabelle is seriously injured when she takes a classroom hostage.