A small American town is left reeling after two per cent of the world's population inexplicably vanishes simultaneously, an event referred to as the Sudden Departure. The series follows a local police chief and his fractured family as they struggle to maintain order and personal stability in the years that follow, surrounded by grieving neighbours and radical new cults that have emerged in response to the tragedy. Questions of faith, guilt, and the meaning of loss drive the characters as they search for ways to carry on living in a world that may never have answers.