The title you're asking about, is a psychological horror film that follows a woman named Sara who wakes up from a coma with no memory of her past. The Story Setup

In the real world, a priest is performing an exorcism on her in her parents' home. The struggle she feels in the movie is her soul's battle to break free from the demonic influence and return to consciousness.

The movie eventually shifts from a standard "gaslighting" thriller into something much more supernatural.

After a traumatic event—implied to be a suicide attempt—Sara finds herself under the intense care of her husband, , in a secluded, lavish home. Nick appears to be the perfect, doting husband, helping her piece her life back together. However, as Sara explores her surroundings, she begins to notice disturbing inconsistencies:

The household staff and even Nick himself begin to act in increasingly sinister and controlling ways, making Sara (and the audience) doubt what is real. The Twist Ending