Trapped in Tia Juana

In 1910, at Fort Crockett near the Mexican border, Colonel Holbert learns that his twin boys, Johnny and Kenneth, are missing. Although Kenneth is found, Johnny is kidnapped after his soldier suit is stripped of its buttons. Years later, Kenneth graduates from a military academy and requests duty at Fort Crockett. At his graduation reception, Emma Brandon observes that Kenneth has fallen in love with her niece, Dorothy. After a week's stay, Dorothy and Aunt Emma prepare to leave for Mexico, when Kenneth gives Dorothy an engagement ring. Meanwhile, Sheriff Dean comes to ask Holbert for the army's help in capturing the bandit, El Zorro. The banker Mr. Lee explains that El Zorro robbed him the night before and left a pile of I.O.U.'s and a letter apologizing for being overdrawn. As Dorothy and Aunt Emma travel in an autostage, it is held up by El Zorro, who takes their money box and leaves a receipt. Further up the hill, the stage is robbed a second time by the bandit Lopez, and the driver tells him that El Zorro has beaten him to it. Lopez then kidnaps Dorothy and takes her to a cantina, where El Zorro sits drinking. As Lopez toasts her beauty after threatening to sell her to a group of Mexicans, a bullet knocks the glass out of his hand. El Zorro rescues Dorothy and takes her to his house with the promise that she will be returned safely. Dorothy makes dinner and tells El Zorro that he looks like someone she knows. He notices her ring and tells her he knows of one that will look much better on her finger. While she is sleeping, El Zorro travels into town and returns with a box full of clothes and some comfortable boots for her to wear. As he helps her on with the boots, she notices his necklace of army buttons. Back at the fort, they receive word from the sheriff that Dorothy was rescued by El Zorro. Holbert gives Kenneth permission to look for Dorothy, but she returns before he can leave. That night, El Zorro climbs up to Dorothy's window to give her a diamond ring. Just then Kenneth knocks, and El Zorro escapes in Kenneth's car with the sentry firing after him. After Kenneth leaves in pursuit of El Zorro, Dorothy tells Holbert about the necklace of buttons, and they conclude that El Zorro is Johnny. When Kenneth arrives at El Zorro's house, Lopez is already there. Lopez shoots El Zorro and escapes, and when Kenneth recognizes his brother, he tries to help him. Holbert and Dorothy arrive, and the three of them try to persuade El Zorro to return to America, but El Zorro faces jail in America. He decides to stay in Mexico with Dorothy, who tells the heartbroken Kenneth that she is remaining to help Johnny begin his new life.