Both Linda Roberts (Judi Meredith) and Amos Crenshaw (Frank Overton) have sworn vengeance against Joe Cartwright. Linda thinks that Joe killed her brother, while Amos' son was shot by Joe in self-defense. The tension reaches the boiling point when Linda hires a man to assassinate Joe, then changes her mind-only to realize that she doesn't know the true identity of the killer. Cowritten by Bonanza star Michael Landon and Joy Dexter, "The Wormwood Cup" (a title explained in the context of the episode) first aired on April 23, 1967. ~ Hal Erickson, Rovi