S1, E20: The Ingalls receive a midnight visit from Will O'Hara, a traveling circus man who, with his irresistibly charming demeanor, persuades Charles to let him set up in front of their home. When O'Hara's "magic powers" nearly cost an appendicitis-stricken Mrs. Oleson her life, Charles asks him to leave town--only to track him down again in the wake of a family crisis.