Hopalong Cassidy: Law of the Pampas

While driving cattle to the ranch of Senor Valdez in Argentina, Hoppy runs into a strange tryst between Merritt, Valdez's foreman, and a girl. Valdez's son and daughter have both been recently killed. Merritt was to marry Valdez's daughter, and stands to inherit the ranch. Unknown to everyone, Merritt is carrying on a romance with another girl. Since Hoppy discovered them meeting in secret, he is a threat to their plans. Hoppy is tricked into a meeting where he is caught by Merritt's men.