After escaping the alternate Topeka and the evil wizard Randall Flagg, Roland's ka-tet travel to the farming village of Calla Bryn Sturgis where they meet the townsfolk, as well as Father Callahan, who was originally introduced in 'Salem's Lot. He and the townsfolk request the ka-tet's assistance in battling against the Wolves of Thunderclap, who come once a generation to take one child from each pair of the town's twins. After a few months of being away, the children are then returned "roont" (ruined) - mentally handicapped and destined to grow to enormous size and die young. The Wolves are due to come in about a month's time.