12-year-old George Mellish, tired of beatings for both real and fancied misdeeds at the hands of his foster parents,runs away from home by hopping a freight train and lands somewhere east of the Mississippi River. The first person he meets is Dirty Jim Helliman who lives in a fantastically filthy hovel and with whom George feels a kindred spirit, both having "suffered" at the hands of a clean woman. It is (really dirty) Dirty Jim that tells George of the mythical, eight-foot bogey man called "The Fool Killer." George gets sick and Dirty Jim takes him to town where Mrs.Ova Faversham takes charge of the feverish boy. When Blessing Angeline, Mrs. Faversham's 10-year-old daughter, tells George that her mother intends to return him to his foster parents, George hits the road again. He meets Milo Bogardus, a young Civil War veteran, who has been robbed of his memory by a war wound, and is as lost in his own way as George. THey come upon a camp meeting, where the fanatical Reverend Spotts is conducting a revivalist meeting and during the religious frenzy, George blacks out. He comes to and is alone, and is unaware that the Reverend has been murdered, and starts in his search to find Milo. He finds a home with the Dodds, small town store keepers. When, at supper, Dodds makes mention of the murder of the Reverend Spotts, George blurts out that "The Fool Killer done it" and tells them the legend as told to him by Dirty Jim. That evening, while George lies in bed, a shadow appears at his window. It is the figure of a tall, gaunt apparition, ax in hand ready to strike---"The Fool Killer!"