Gary Navarro, a minor league baseball player back after a 30-year absence, finds that hearing everyone's unspoken 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 Gary with getting his life back. As the case occupies the majority of his time, Tom finds himself struggling with his responsibilities 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 younger sister April, and as Richard, Lily, and Isabelle continue their life on the run, Richard grows increasingly disturbed by his daughter's apparent abilities.
The 4400 tells the stories of 4,400 people who disappeared over a period of fifty years and who all reappear at the exact same time without any memory of where they've been and what happened to them. Some of them have been altered and have strange abilities, both good and bad.
The series kicks off with a ball of light sailing toward Earth, but rather than the expected catastrophic event, thousands of people emerge from the ball of light. The returnees have been missing from a few years to several decades and no one has aged a day.