The Summer of Miss Forbes

Eduardo and his wife leave for a six-week cruise from Miami, leaving their seaside house in Yucatan behind. The mother hires Mrs. Forbes, a German governess, to take care of Mauricio and Sandro and to implement strict discipline. Forbes arrives by boat and is immediately assigned the task of imposing 'law and order' in the home.

Once in charge, Forbes adopts an authoritarian, formal approach and enforces harsh routines on the two boys. The children respond with resentment and resistance as rules become stricter than before. The household mood shifts as Forbes asserts control over every aspect of the daily life.

Mauricio and Sandro secretly observe Forbes at night and discover her private habits. They see her drinking, eating sweets, and reading loud passages in German, revealing a human, unguarded side behind the stern exterior. The revelation deepens their sense of resentment toward her rule.

Forbes becomes infatuated with Aquiles, the hunky young scuba instructor who spends a lot of time with the children. She narrates a mythic tale of Achilles and Penthesilea to seduce him, exposing a longing for freedom more than a genuine connection. Aquiles, younger and wary, resists her advances outright.

After much persistence, Forbes persuades Aquiles to go into town for drinks. There, she drops her facade and speaks openly about hating restraint and wanting to live freely and passionately. Aquiles remains indifferent, keeping his distance and revealing his own hidden reservations.

The next night, Forbes secretly follows Aquiles to his rustic cabin and finds him naked in the company of a male lover. Before she can be discovered, Forbes sets the house on fire with the two men inside, destroying their clandestine world and marking a violent turn in the story.

The following morning at breakfast, Forbes receives a letter that shakes her, though its content remains unrevealed. The message hints at consequences that threaten her grip on the household. The tension in the house grows as she processes the unknown communication.

Inspired by the unresolved letter, Mauricio and Sandro resist Forbes' orders and disobey with renewed vigor. Forbes, pushed to her limit, finds herself unable to enforce the discipline with the same rigidity as before. The boys seize the chance to exercise their fledgling freedom around the house and at sea.

The brothers recall Forbes forcing them to eat moray, the fish they once feared; driven by fear and a sense of justice, they decide they can kill Forbes and escape punishment. They plot to poison her tequila, with Sandro pushing forward while Mauricio warns of potential consequences. The plan marks a drastic escalation in their rebellion.

The boys execute their plan and poison Forbes's tequila. The next morning they wake, assuming the plan worked, and celebrate their freedom by going scuba diving. Their sense of triumph is short-lived as the reality of the crime begins to surface in the house.

When they return, the beach house is in turmoil and Forbes has been killed, stabbed multiple times. Mauricio and Sandro avoid the police guarding the scene and slip into Forbes's bedroom to view the body. Her face bears an unsettling serenity, suggesting a grim peace in death.

With Forbes dead, the regime is broken and the house is left in a state of turmoil. The boys evade immediate punishment, but the consequences of their actions linger in the unsettling stillness around the tragedy. The film closes on a haunting note, leaving the future of the boys and the house uncertain.