Lightships (1970)

Eve awakes in an unstaffed medical facility with no recollection of how, why or when she was admitted. She joins a group of outcast patients, who are attempting to recall what takes place during treatment. As Eve learns more about the patients, she begins to remember the terrible events that led to her sickness. An alien world at the edge of her dreams begins to bleed through, compelling her to write the transmissions down. Soon, these visions will consume her. Is she a prisoner, a patient... or dead?