Beginning where book six left off, Jake Chambers and Father Callahan battle the evil infestation within the Dixie Pig, a vampire lounge in New York City featuring roast human flesh and doors to other worlds. After fighting off and destroying numerous "Low-Men" and Type One Vampires, Callahan sacrifices himself to let Jake survive. In the other world, Fedic, Mia, her body now physically separated from Susannah Dean, gives birth to Mordred Deschain, the biological son of Roland Deschain and Susannah. The Crimson King is also a "co-father" of this prophetic child, so it is not surprising when "baby" Mordred's first act is to shapeshift into a spider-creature and feast on his birth-mother. Susannah shoots but fails to kill Mordred, eliminates other agents of the Crimson King, and escapes to meet up with Jake at the cross-dimensional door beneath the Dixie Pig which connects to Fedic. Maturing at an accelerated rate, Mordred later stalks Roland and the other gunslingers throughout this adventure, shifting from human to spider as the need arises, seething with an instinctive rage toward Roland, his "white daddy."