Rustlin' for Cupid (1926)

Bradley Blatchford, returning to his father's ranch from college, meets Sybil Hamilton, who is coming to the ranch town as a schoolteacher. Later, Bradley's father is suspected of rustling cattle, but he denies the charge. As the romance develops between Bradley and Sybil, Bradley comes upon a rustler at work and is about to shoot when he discovers his own father, who claims he is victim of a hereditary taint that he cannot subdue. Some friends, who observe the incident, rustle some of Blatchford's cattle, mark it with Sybil's brand, and accuse her of rustling and hiding some dark secret. She confesses that her brother disgraced the family, and when George learns of it, he is forgiven and is reunited with her.