Over the past century, 4400 individuals who were neglected, underestimated, or marginalized disappeared without explanation. Suddenly, they all reappear at once, unchanged by time and with no recollection of their experiences. As authorities hurry to assess any possible danger and manage the narrative, the 4400 must come to terms with their return, which includes some enhancements. They also face the growing possibility that their simultaneous return serves a particular purpose.