In the pilot episode, what was originally thought to be a comet deposits a group of exactly 4400 people at Highland Beach, in the Cascade Range foothills near Mount Rainier, Washington. Each of the 4400 had disappeared at various times starting from 1946 in a beam of white light. None of the 4400 have aged from the time of their disappearance. Confused and disoriented, they remember nothing of events occurring between the time of their disappearance and their return.