The year is 1950. The place is Hillside State Mental Hospital located outside of Chicago. At the time, the treatment of the mentally ill was archaic, consisting of hydrotherapy, electroshock therapy, Insulin coma therapy, and, in the extreme, pre-frontal lobotomy. Tranquilizers were not yet available.

Mary Lou Hammond and Kate Stephens were among the student nurses taking their three month psychiatric rotation at Hillside.
Mary Lou is an extremely sensitive young lady. She begins dreaming about a woman in the early part of the century. The dreams tell a continuing story. Soon Mary Lou finds messages in mirror image writing from the woman in her dreams, Margaret Montague. She claims to have died in 1911. If this entity does exist, what does she want from Mary Lou?

As the students go from one terrifying experience to another in the institution, Mary Lou’s dreams intensify, and so do the messages. She becomes obsessed with finding proof that the woman did exist as the story escalates to its life-threatening climax.