In a world where grief can be a tangible, consuming force, Brón follows a young woman named Saoirse who returns to her family's remote coastal village after the sudden death of her mother. As she sifts through the belongings of the woman she barely knew, Saoirse begins to uncover a hidden history steeped in ancient folklore and a mysterious, sorrowful entity known only as the Brón. This spectral presence, a manifestation of deep-seated familial anguish, begins to haunt her, feeding on her own unresolved pain and threatening to pull her into an abyss of despair. Saoirse must confront the dark secrets her mother kept and the legacy of heartbreak that has cursed her lineage. Guided by a reclusive local historian played by Cillian Murphy and the fragmented memories of her own childhood, she embarks on a harrowing journey to break the cycle of sorrow before it claims her entirely. Blending atmospheric horror with a poignant family drama, the film creates a chilling yet deeply moving exploration of how we carry our losses and the strength required to let them go.