Broncho Billy, the mail carrier, ejects a greaser from the post office for pushing a girl out of his way. The half-breed is thoroughly angered and swears revenge. Broncho then goes home, and on his way loses his mail bag. He does not miss it, so goes to bed that night unaware of his loss. The girl he protected at the post office finds the mail bag, and when she approaches Broncho's shack to return it she sees the greaser prowling about. She hastens to a dance hall, where she tells her friends of Broncho's danger, and she leads the way back to his shack, where they arrive just in time to save him from being stabbed while asleep.
—Moving Picture World synopsis