The Avengers (1950): film synopsis (warning — has spoilers!)

A young Francisco Suarez (John Carroll) sees his father murdered by a notorious bandit known only as El Mocho. When he is older, he vows revenge and seeks out the bandit. In Buenos Aires, he rescues Andre LeBlanc (Fernando Lamas) from a duel with the ruthless Colonel Luis Corral (Roberto Airaldi). Corral is second-in-command to the governor, having finagled an engagement to the governor’s daughter Maria Moreno (Adele Mara) in order to further his political career. Once Corral and Maria are married, Governor Don Rafael Moreno (Jorge Villoldo) plans to pass on his governorship to Corral. However, Corral would rather be with his mistress, the Countess Yvonne (Mona Maris). He believes that if Maria breaks off their engagement, the governor will feel so guilty that he will give Corral the governorship anyway. Hearing that Suarez has a way with the ladies, Corral arranges a bet with him. If he can win the affections of Maria, Corral will return the hacienda he has swindled from LeBlanc. If Suarez loses the bet, he promises to become Corral’s servant. Meanwhile, it becomes clear to the audience that Corral’s henchman Lt. Hernandez (Vincente Padula) is actually the bandit El Mocho who Corral helped to fake his death, by pretending to have slain El Mocho in a duel.

Suarez begins romancing Maria, and though she seems attracted to him, she feels he is too brash and rebuffs him. Later that night, Maria awakens to Suarez serenading her from down in the garden. The next morning, while attending a ceremony blessing the children of the fishermen, Maria’s necklace drops into the sea. None of the divers are willing to retrieve it as a shark is spotted nearby. Only Suarez is brave enough to dive in after it, but after killing the shark and finding her necklace, Suarez surfaces behind some rocks and sees how concerned Maria is for his safety. He decides to hide himself and let her believe he is lost at sea. Believing Suarez to have been killed by the shark, Maria then realizes that she truly cares for him, and when he appears in her garden later alive and safe, claiming to have hit his head on a rock, she confesses her love for him. Suarez, who has also fallen in love with Maria, decides to do the noble thing and tell Corral that he has lost the bet and will become Corral’s servant. Corral becomes angry and impatiently tells Suarez to leave the colony and never come back. When she hears that his engagement to Maria has not been broken off, Countess Yvonne becomes so jealous that she tells Maria of the bet. Maria is heartbroken, and tells her father that she will not marry Corral, and warns her father against Corral’s political ambitions.

His goal for political control thwarted, Corral convinces Hernandez/El Mocho to assemble his old bandit gang and attack the city. During the attack, Suarez rushes to the governor's house to protect Maria, but is unable to stop El Mocho from killing her father. Suarez is knocked out, but is rescued by LeBlanc. When Suarez regains consciousness, LeBlanc informs him that Corral has taken control of the city and that El Mocho’s men have kidnapped Maria.

Suarez and LeBlanc return to the Governor’s house to confront Corral, just in time to discover that Corral has killed his accomplice Lt. Hernández/El Mocho. Suarez insists that Corral reveal where Maria is being held prisoner, and they have a duel in which Suarez disarms Corral. Then Corral is accidentally killed by a servant, Sancho.

Suarez sets out to rescue Maria, but when he discovers El Mocho’s hideout, he finds Yvonne instead. Yvonne explains that she changed places with Maria, and that Maria is hiding at the Convent. Suarez convinces Yvonne to return to the city with him.

Upon their return, Suarez and LeBlanc ride off to rescue Maria but they are stopped and arrested, falsely accused of Corral’s death. While imprisoned in the city jail, a mob of angry townspeople gather outside, determined to lynch the two men who they believe are murderers. As they await certain death, the crowd outside the jail suddenly goes silent. It is revealed that Yvonne has brought Maria to the townspeople to explain the truth about Colonel Corral’s treachery, and they have gone silent because they have been listening to her. Suarez and LeBlanc fling open the jail doors prepared to meet an angry mob, only to discover Maria outside, surrounded by the townpeople. Suarez and LeBlanc are exonerated, and the lovers are reunited.