Nathaniel Ayers is the titular character in The Soloist. A talented musician, Ayers trains at Julliard in the ‘70s before he drops out as a result of his schizophrenia. He goes through years of treatment but abandons it to come to California in search of a father who had abandoned the family many years before. Eventually, Ayers becomes homeless and keeps all of his possessions in a shopping cart. He sleeps in the Second Street tunnel where he plays his violins for passers-by. Lopez notices him one day, and the two form a relationship.

Mental illness is a central theme of the novel, and a central aspect of Ayers’s life. As a paranoid schizophrenic, Ayers often loses touch with reality and with himself. Ayers notes: “My mind would not strive to do what’s best for Nathaniel” (79).Ayers acknowledges that his own mind is against him—it causes him to indulge in destructive behavior. Gradually, Ayers battles his mental illness throughout the novel and moves towards recovery. A significant step is leaving the Second Street tunnel and moving into an apartment. Although Ayers does not take medication or go to therapy during the book, he nonetheless moves closer to a more mentally stable way of life.