When the 'Captain Trips' flu epidemic wipes out more than 99% of the population, the remaining few immune to the disease—including Stu Redman, Frannie Goldsmith and Harold Lauder—set out in search of other survivors. While doing so, they experience visions of the nurturing Mother Abagail and the menacing figure of The Dark Man.
Musician Larry Underwood is on the cusp of his big break when "Captain Trips" strikes New York. Alone and wandering an empty city, he meets an alluring new acquaintance also desperate to escape. Meanwhile, an incarcerated Lloyd Henreid comes face-to-face with Randall Flagg, The Dark Man himself, who makes him an enticing offer.
Mother Abagail selects a surprising voice to be her conduit to her chosen Committee in Boulder: the young deaf man Nick Andros. The arrival of a disturbing visitor to the Boulder Free Zone, shakes the Committee and Boulder residents to their core. Elsewhere in the Free Zone, Nadine Cross is haunted by a childhood memory.
Nadine and Harold's dark intentions continue to take shape. The Committee's spies entrench themselves in New Vegas, where Flagg is building his own society, where officially-sanctioned sin and debauchery disguises a ruthlessly-enforced order. Frannie hatches a plan to confirm her suspicions of Harold. Mother Abagail seeks divine council.