When the Captain Trips flu epidemic wipes out more than 99% of the population, the remaining few immune to the disease set out in search of other survivors.

Musician Larry Underwood is on the cusp of his big break when Captain Trips strikes New York; wandering alone, he meets an alluring new acquaintance also desperate to escape; an incarcerated Lloyd Henreid comes face-to-face with Randall Flagg.

Mother Abagail selects a surprising voice to be her conduit to her chosen committee in Boulder, Nick Andros; the arrival of a disturbing visitor to the Boulder Free Zone shake residents to their core; Nadine Cross is haunted by a childhood memory.

The Boulder Free Zone Committee look to assert their position in the community with a town hall meeting, but Flagg plots to destroy the group from within.

Nadine and Harold's dark intentions take shape; the Committee's spies entrench themselves in New Vegas, where Flagg is building his own society; Frannie hatches a plan to confirm her suspicions of Harold,while Mother Abagail seeks divine council.

While all of Boulder fears for Mother Abagail's safety, Stu organizes search parties to ensure her return, presenting an opportunity for Harold and Nadine; in New Vegas, Flagg recruits a dangerous new follower.