As a British airliner makes an emergency landing during a wartime evacuation on a deserted Pacific island, fate strikes a harsh blow to its young passengers. Just a handful of preadolescent boys emerge as the sole survivors, their innocence and resilience quickly put to the test. Ralph, a light-haired boy with a natural talent for leadership, seizes control using a conch shell—his symbol of authority. He establishes three main goals: to enjoy carefree freedom, to survive against all odds, and to keep a signal fire burning as a beacon of hope for any passing ships.
Together with red-haired Jack and the quiet Simon, Ralph uses Piggy's glasses to ignite a signal fire that symbolizes their growing friendship. However, as time goes on, the fragile sense of order begins to erode. The boys become complacent, disregarding Ralph's efforts to better their lives on the island in favor of succumbing to paranoia about an imagined creature they've named "the beast." Despite Ralph's attempts to instill rational thought, Jack exploits their fear, pledging to slay the beast himself. As the smoke signal weakens and a ship sails by unnoticed, Ralph faces Jack in a fierce confrontation, pondering whether to step down from his leadership position.
Ultimately, it is Piggy's practical advice that sways Ralph to hold onto his role, even as the island's tenuous social structure continues to unravel. One memorable night, the distant sounds of an aerial battle fill the air, with a lifeless fighter pilot's body descending slowly on a parachute. Twin brothers Sam and Eric mistake this corpse for the beast, sending ripples of terror through the group. Ralph, Jack, and Roger investigate the mysterious figure, only to flee in fear, convinced of the beast's reality. Jack sees this as an opportunity to turn the others against Ralph and begins assembling his own tribe, gradually recruiting more boys with promises of excitement and freedom.
In a chilling ritual, Jack's tribe constructs a grotesque offering for their imagined predator: a bloodied pig's head placed on a makeshift pike, surrounded by a swarm of flies. Simon, who often wanders alone in the woods, finds himself in a disturbing conversation with this repugnant trophy, which he names the "Lord of the Flies." The severed head murmurs sinister truths to him, warning that his fellow castaways will betray him and that no actual monster exists among them. That same night, Ralph and Piggy visit Jack's tribe, now transformed into wild, face-painted revelers lost in their primal celebration.
When Simon realizes that their shared terror has given life to an imaginary beast—an innocent pilot—he rushes to share this revelation with Jack's tribe. Tragically, the frenzied group, including Ralph and Piggy, mistakes this innocent messenger for their dreaded creature, brutally beating him to death.
As Jack's tribe steals Piggy's glasses, the only means to start a fire, Ralph teams up with Piggy, Sam, and Eric to confront Jack's group and recover the stolen item. However, a treacherous trap set by Roger results in Piggy's demise, shattering both his body and the conch shell that had upheld their fragile order. In a desperate bid for survival, Ralph narrowly escapes, but Sam and Eric ultimately yield to Jack's merciless authority.
That night, Ralph sneaks away to warn Sam and Eric, who inform him of Jack's malicious intent to hunt him down. The next morning, Jack's tribe unleashes a fiery destruction upon the island, laying waste to everything in its path. Ralph barely escapes the inferno, facing the grim reality of their shattered existence. As he collapses before a British naval officer—who has arrived to investigate the fire—the boys dissolve into tears, mourning the loss of their once-cherished innocence. The officer's face reveals disappointment and disgust as he surveys the savage behavior of these lost boys, ultimately turning away to gaze at his waiting cruiser offshore—a stark reminder of their irrevocable decline.
