A group of Anglican nuns, led by Sister Clodagh, is sent to a remote, mountainous region in the Himalayas to establish a mission in a former palace that was once used as a women's pleasure house. Their task is to set up a school and hospital while grappling with the cultural and environmental challenges of their new surroundings. The palace’s isolation and the exotic beauty of the locale begin to affect the group's sense of purpose and religious commitment, especially as they interact with the local inhabitants and begin to confront their own pasts and desires.

Sister Clodagh encounters Mr. Dean, a British agent who lives nearby, whose laissez-faire attitude and rugged charm create tension and challenge her authority and sense of duty. The local environment, combined with Dean’s presence, starts to erode the nuns' discipline, leading to increasing instability within the group. Sister Ruth, in particular, begins to experience severe emotional and psychological strain. As these internal and external pressures mount, the nuns' mission faces severe jeopardy, bringing underlying tensions and crises to the surface.