Gunsmoke - Season 7 Episode 4

Sarah Cooley, dying of a heart attack, confesses to her husband, Gip Cooley, that her father changed his last name from Harper to Harris long before they were married. Harper was known for killing over 100 men, and Sarah wanted Gip to know about this so that he can raise his sons accordingly. She's convinced the bad blood has been passed on. Gip promises to be strict with them and Sarah passes on. Years later, with the boys, Kyle and Jeff, in their mid-twenties, Jeff accuses neighbor Carr of selling him a horse that's blind in one eye, but Carr won't buy it back. Kyle falls in love with saloon girl Jenny, but she marries Carr instead because he has his own ranch. She soon realizes it's a mistake and starts meeting Kyle on the sly. A plan is engineered to kill Carr and set Jeff up to take the fall for it!