 1946. Young Maia Rutledge sees a bright light and then disappears from the face of the Earth. She s the first in a long string of disappearances going on for years. 2004. A comet is on a collision course with earth. Suddenly it stops and leaves 4400 people behind. All had disappeared and haven t changed a bit from the moment no one ever saw them again. While agents Tom Baldwin and Diana Skouris have the task to investigate what happened, some of The 4400 are behaving strangely and seemingly possess extraordinary powers.