The Rifleman S01E25 - One Went to Denver

Lucas welcomes an old friend who turns up at his ranch for an unexpected visit. Knowing that his friend Tom Birch has a reputation for lawlessness, Lucas is at first concerned but then is reassured by Tom's statement that he is just passing through North Fork on his way to Denver. Later, however, Lucas finds himself involved in a plot to rob the North Fork Bank and must choose between backing up the Marshal and helping the friend who once saved his life.