The Ward (2010)

In rural Oregon, at the North Bend Psychiatric Hospital in 1966, a young patient named Tammy is killed by an unseen force at night.

Kristen, a troubled young woman, sets fire to an abandoned farmhouse and is arrested. The local police take her to North Bend, where she meets the other patients in the ward: artistic Iris, seductive Sarah, wild Emily, and child-like Zoey. Kristen is taken to a room previously occupied by their friend, Tammy, and meets therapist Dr. Stringer. She reveals that she is unable to recall anything about her past. She is attacked by a horribly deformed figure that had been staring at her earlier, but upon telling the nurse this, she is drugged and put through intense electroshock therapy.

Dr. Stringer uses hypnotherapy to unlock Iris's hidden memories. After the session, Iris is killed by transorbital lobotomy by the deformed figure. Kristen finds Iris' sketch of her attacker with the name 'Alice Hudson', a former patient at the hospital. That night, Kristen and Emily attempt to find Iris and escape. However, Kristen is thwarted by Alice and loses consciousness while Emily is caught.

Alice kills Sarah. Kristen discovers that all the girls had killed Alice together because Alice constantly hurt them. Now she is after the girls for revenge. Kristen tries to talk Emily down from attempting suicide but Alice kills her by slitting her throat with a scalpel. Kristen plans to escape again by holding Zoey as a pretend hostage but is drugged and placed in a straitjacket. She escapes it and she and Zoey try to get out. Zoey is killed by Alice off-screen. After a lengthy chase, Kristen seemingly manages to destroy Alice. She finds Alice's file in Dr. Stringer's office, which has each of the girls' names, including Kristen herself.

Dr. Stringer, catching her in his office, reveals that Kristen is actually one of many personalities of the real Alice Hudson, who was kidnapped at age eleven, eight years earlier, and left chained for two months in the basement of the same farmhouse Kristen burned down. In order to survive the trauma, she developed Dissociative Identity Disorder, creating each one of the girls from the ward as a different personality. Over time, Alice's own personality became so overwhelmed by the others that she became lost. Dr. Stringer attempted experimental techniques to bring Alice's own personality back, resulting in the manifestation of Ghost Alice, who destroyed the individual personalities one by one. Her treatments were working until 'Kristen' appeared, as an attempt of Alice's mind to protect the other personalities so she wouldn't need to face her trauma.

As the Kristen personality tries to come to terms with all this, Ghost Alice appears before her and the two begin to fight, each determined to emerge as the dominant personality. During this hallucinatory altercation, "Kristen" falls out the window and hits the ground several stories below. Alice manages to survive the incident, and the Kristen personality finally fades away, reverting Alice to her true self. While being treated for her injuries, Alice is visited by her parents, whom her other personalities had originally written off as strangers. She tells Dr. Stringer that she remembers what happened and finally accepts that she has to face her trauma, resolving not to run from it anymore.

At the end of the movie, Alice, who has seemingly been rehabilitated, packs her belongings as she prepares to leave the hospital. But, when she opens the medicine cabinet above her sink, Kristen lunges out at her, suggesting that the personality is still strong and refuses to be destroyed.