On a serene Valentine's Day in the year 1900, a group of female students from an Australian boarding school, accompanied by their headmistress and a teacher, embark on an outing to Hanging Rock, a mysterious geological formation in Victoria. Dressed in their white muslin dresses, the girls enjoy the idyllic setting, unaware of the strange events that will soon unfold. The atmosphere is filled with a sense of foreboding as the rock's eerie beauty and the brooding landscape set the stage. After lunch, a small group of girls, drawn by an inexplicable curiosity, decide to explore the rock further. Their teacher, strangely affected by the location's atmosphere, permits their venture. Meanwhile, the rest of the party remains behind, lounging in the pastoral tranquility.

The excursion takes a dark turn when three of the girls and one of the teachers mysteriously vanish without a trace on the rock. The disappearance throws the school and its surrounding community into turmoil, sparking a fraught search that yields more questions than answers. The landscape, with its foreboding monoliths and hidden crevices, becomes a labyrinthine puzzle. Echoes of the missing persons linger in the air, fueling speculations and rumors about the nature of the rock and the fate of those who disappeared. As investigators and the remaining members of the picnic grapple with the unknowable, the incident leaves an indelible mark on the community, intertwining with their lives and altering their understanding of the world around them.