Irene and Franklin York, a retired couple, have a secret: a Chamber buried in their backyard that miraculously leads to a strange, deserted planet. When an enigmatic young man arrives, the Yorks quiet existence is upended and the mysterious Chamber they thought they knew so well turns out to be much more than they could have ever imagined.

In a world mostly wiped out by the plague and embroiled in an elemental struggle between good and evil, the fate of mankind rests on the frail shoulders of the 108-year-old Mother Abagail and a handful of survivors. Their worst nightmares are embodied in a man with a lethal smile and unspeakable powers: Randall Flagg, the Dark Man.