The world as we know it has ended.
A computing error in a US Government Defence Department laboratory cascades into the apocalypse. A deadly bio-weapon is release which infects all personnel in the military compound and the leak automatically triggers an immediate lockdown of the facilities. But the containment isn't quick enough to stop soldier Charles Campion, who escapes to his residence and then leaves the facility with his wife and child before anyone figures out what has occurred. His escape and subsequent contact with his family and the outside world spread the bug to everyone he comes in contact with - and with a near perfect infection / kill rate the pandemic / apocalypse begins.
The virus - named Captain Trips - is compared with a wildly successful chain letter that zips through the population. It kills the host in a matter of weeks, leaving no time for any public health officials to develop a vaccine, inoculation or to prepare any isolation measure. The virus has no weakness - there is no trade-off between its infectiousness and mortality as both are virtually absolute. Except for a fraction of a percent of the population who are mysteriously immune everyone else dies.
No governments, institutions or societies remain; civilization is pushed back a few millennia. The survivors group together in the aftermath of the pandemic, and find a calling in their dreams where they see one of two figures. The supernatural element of the story begins with these dreams. Those that see Mother Abigail become the good guys and she exalts her followers as God's chosen one. The ones that see Randall Flagg acquiesce his demand for total allegiance in his plan for chaos.
Mother Abigail is a 108 year black old woman located in Hemingford Home, Nebraska and Flagg is a middle aged man in Vegas, Nevada. Good versus evil, age versus youth, small town folk versus sin city dwellers, minority versus majority, still versus motion reinforce in differentiate the protagonists and antagonists.
Stephen King explores illustrates how people with their own diverse flaws, prejudices and experiences act under pressure in this good versus evil setting. The story is told through the baggage the characters carry, and how each one deals with their new realities and their choices. The horror is built up in the beginning through the challenges faced during normal times - the flagging economy of a small town, the effects of new found fame, an unplanned pregnancy, a barroom brawl. The flu which moves comparatively fast begins by creeping stealthily through mundane lives lending to a slow burn of horror in the start.
Stu Redman is one of the last to get infected by Charles Campion, and one of the first found to be immune to the virus. Cast as the strong, silent type - he gives the immunologists a tough time when they don't give him answers and isn't above being mischievous with them. Described as probably the quietest man in the town of Arnette, Stu lost his wife and child a few years before the story begins; and the momentum of habit kept him in small-town America while his surviving brothers moved ahead in life.
Before the virus enters her life Fran Goldsmith's problem is a pregnancy out of wedlock with the child of a wannabe poet. She is the only surviving child of a couple who lost their son years ago. After the loss Fran's mother shut herself in emotionally. Fran's father's approach to the birth of his grandchild is more humane.
Larry Underwood is recovering from instant (but still mediocre) fame as his single climbs the charts. Success and its trappings quickly take over his life, having seen so much liquidity for the first time in his life till a friend straightens him out. He finds refuge with his mother and waits for his next royalty cheque to come in to pay off his dealer.
Dark dreams that warn of the coming of the dark man. The apostate of death, his worn-down boot heels tramping the night roads. The warlord of the charnel house and Prince of Evil. His time is at hand. His empire grows in the west and the Apocalypse looms. When a man crashes his car into a petrol station, he brings with him the foul corpses of his wife and daughter. He dies and it doesn't take long for the virus which killed him to spread across America and the world.