Synopsis by Hal Erickson
Based on a story by Rex Beach, Heart of the Sunset takes place somewhere along the Rio Grande. Neglected by her philandering husband, Alaire Austin (Anna Q. Nilsson) falls in love with dashing Texas Ranger Dave Law (Herbert Heyes). She also attracts the attention of Longorio (E.L. Fernandez), a notorious Mexican bandido. When Alaire is compelled to visit Mexico on family business, Longorio invades her ranch and kills her husband. Normally, this would give Dave Law a clear field, but he dare not marry Alaire because of an inherent streak of insanity in his family. This plot point is briefly forgotten when Longorio captures both Alaire and Dave and begins playing a deadly cat-and-mouse game with his prisoners. Eventually, Longorio is disposed of, while Dave learns to his delight that he is an adopted son, and thus not in danger of going bonkers.