What is the main conflict in Wolves of the Calla by Stephen King?

Wolves of the Calla is the fifth novel in the Dark Tower series by Stephen King. In this novel, Roland and his ka-tet, Eddie, Susannah, and Jake, are following the Path of the Beam in their quest to find the Dark Tower when they are met by a group of people from a nearby community called Calla Bryn Sturgis. These people have been plagued by what they call Wolves for many generations. The Wolves come to their community and steal one child from every set of twins born in the community, only to return them weeks later with brain damage and a tendency to grow to giant size. Some people in the community want to stand up against these Wolves for the first time and are eager to enlist the gunslinger's assistance. At the same time, Eddie has made the ka-tet aware of a potential problem for a rose that exists in 1970s Manhattan that is somehow connected to the Dark Tower. Roland, too, has discovered a problem with Susannah that he has chosen not to tell anyone, including her husband. Wolves of the Calla is a continuation of Roland's quest for the Dark Tower that sidelines the ka-tet and leaves the reader anxious to see if they can survive yet another set of travails.