A stranger in town meets pretty young Susan Martinez De La Cruz and accompanies her to a barbecue , where wealthy Jason Carberry is saying a few words for the recently departed Robin Randall , a citizen who got shot .  Jason objects to the stranger's presence , being Susan's guardian and protective of her .  He challenges him to a shootout , but the stranger pulls his pistol before Jason's can even clear the holster .  Calaveras Kate , a saloon singer who's in love with Jason , is relieved when the stranger declines to pull the trigger .  Rafael Moreno suddenly rides into town and picks a fight with the stranger .  Their brawl continues until the arrival of Judge Wallace Wintrop and his niece , Sheila , who have come to town from back East and deplore all this random violence out West .  The stranger is recognized as Reb Randall , the dead man's brother .  He is looking for the killer , who could be Rafael , or could be Jason , or could even be Billy Buckett , the coward of the county .  The women hold their breath to see if the men they love will survive . 
What is the root cause of all the violence?
Jason was in love with Susan