Taking up where Tracks leaves off, in Four Souls, a strange and compelling woman decides to leave home, and the story begins. Fleur Pillager takes her mother's name, Four Souls, for strength and walks from her Ojibwe reservation to the cities of Minneapolis and Saint Paul. She is seeking revenge on the lumber baron who has stripped her reservation. But revenge is never simple, and she quickly finds her intentions complicated by her own dangerous compassion for the man who wronged her.

The two narrators of Four Souls are from utterly different worlds. Nanapush is both Fleur's savior and her conscience. He tells Fleur's story and tells his own. When his childhood nemesis appears and casts his eye toward his wife, Margaret, Nanapush acts out an absurd revenge of his own and nearly ends up destroying everything. The other narrator, Polly Elizabeth Gheen, is a pretentious and vulnerable upper-crust fringe element, a hanger-on in a wealthy Minneapolis family, a woman aware of her precarious hold on those around her. To her own great surprise, the entrance of Fleur Pillager into her household and her life effects a transformation she could never have predicted. Both narrators come to a deeper understanding of themselves through their relationships with the elusive Fleur Pillager.