Over the last century, thousands of people have gone missing. Suddenly and inexplicably, 4400 missing people are returned, all at once, exactly as they were on the day they vanished. Unclear what this world-altering event means, the government investigates the 4400 to piece together where they’ve been and why they’ve been returned. But slowly the 4400 begin to manifest strange powers, becoming apparent their presence is set to change the human race in ways no one could have foreseen.
Soon, 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, with top agents Tom and Diana investigating the returnees, their abilities and just what that all means for the future of humanity.