In her fourth Bonanza appearance, Mariette Hartley is cast as Lola, a temperamental touring actress. When Lola is forced to kill her abusive boyfriend, Hoss Cartwright gallantly shoulders the blame. This brings down the wrath of Senator Carson (Peter Whitney), the ruthlessly powerful father of the dead man, upon the Cartwright clan. Featured in the cast are Stefan Gierarsch as Grady, Allen Garfield as Charlie, and Mills Watson as Fontaine. First broadcast on November 28, 1971, "The Iron Butterfly" was written by Harold Swanton. ~ Hal Erickson, Rovi