Bad Sister (2025) is a psychological thriller that blends religious symbolism with slow-burning suspense and emotional intensity. Set within the rigid walls of a Catholic prep school, the film explores how authority, faith, and charisma can be weaponized to conceal obsession and control.

The story begins with the arrival of Sister Sophia, a new nun whose elegance, intelligence, and unsettling calm quickly win the trust of students and faculty. Beneath her composed exterior lies a dangerous fixation, carefully hidden behind religious devotion and moral authority.

Her obsession centers on Jason Brady, a kind and principled student with a strong sense of faith and a promising future. Unlike others, Jason represents something Sister Sophia cannot fully dominate, and that resistance only deepens her fixation. What follows is a disturbing psychological game where manipulation replaces guidance.

Zoe, Jason’s younger sister, is the only one who senses that something is deeply wrong. As she tries to expose the truth, she is ignored, doubted, and gradually pushed into isolation. The film effectively captures the fear of not being believed, especially when the threat wears a mask of virtue.