The Other Lamb is a 2019 horror film directed by Małgorzata Szumowska and written by C.S. McMullen. It stars Raffey Cassidy, Michiel Huisman, and Denise Gough.
Selah is a teenage girl, living as part of a cult led by the messianic Shepherd, the only male in the cult. They live in abandoned buildings in the forest and tend sheep. The women are divided into two groups, the younger Sisters, dressed in blue, and the older Wives, dressed in red. As she matures, Selah has become more of a focus of the Shepherd's attention. She frequently wonders about her mother, who died giving birth to her.
One night, Selah overhears a police officer telling the Shepherd that they must leave. The Shepherd announces that he will be leading them on a journey to their new home. During the arduous journey, Selah begins to doubt the Shepherd's judgement. When she sees a car driving on a road, she has a fantasy of herself inside it, dressed as a normal teenager. During the walk, she befriends Sarah, one of the wives who is under punishment for an unspecified sin. Sarah tells Selah that her mother did not die in childbirth, but rather caught an infection and died because the Shepherd would not let her seek medical attention. Sarah admits that she has no faith in the Shepherd but stays because she has no place else to go. When Selah has her first period, she must stay in isolation with Sarah because menstruation makes her "unclean".
The strenuous hike causes one of the wives to go into premature labor, and she dies in childbirth. After the funeral, Sarah tells Selah that she is leaving with the baby. The Shepherd had told them that the baby had to be left behind because it was "born wrong". Sarah reveals that it was a boy and the Shepherd wanted to leave it because "there can only be one ram in a flock".
The Shepherd gets angry at Tamar, one of the sisters, and hits her, further eroding Selah's regard for him. The group arrives at a valley with a large lake, which the Shepherd declares will be their new Eden. The sister's faith has been shaken by the journey, but the Shepherd rebaptizes everyone. That night, he comes to Selah's tent and has sex with her, an act she finds painful and off-putting. She fantasizes about the sisters killing the Shepherd.
The next morning, the sisters awake to find the wives missing. They go to the lake to find the Shepherd kneeling near the wives' robes. He tells them that the wives have ascended into a new life. Selah confronts him, telling him "You are not our shepherd". He smacks her and she hits him back. Some time later, police officers discover the bodies of the wives washed up on the shore of the lake. They also discover the Shepherd's dead body suspended between two trees, a pair of ram's horns placed on his head. The sisters, led by Selah, congregate at a waterfall.