In a bomb shelter outside of Richmond, Virginia, four survivors of a devastating invasion of the country fight for their continued existence. Personal problems begin to divide them, but soon the group faces the very real threat of a quickly diminishing food supply. They must choose between staying within their sanctuary or leaving in hopes of more supplies and the possibility of better lives. They have spent two years under the attackers' radar, safely hidden away, but now their attempts to return to the outside world may be the end of the security and survival they have come to know.