Miss Sidley was a strict and feared teacher who had a knack for catching her students misbehaving. One day, she noticed a student named Robert acting strangely and believed she saw his face change into something evil. This incident haunted her, and she became increasingly paranoid about the children in her class.
After a particularly disturbing encounter with Robert, Miss Sidley took a month off from teaching. When she returned, she was determined to expose the evil she believed was hiding within the children. She brought a gun to school and began taking the students one by one to a secluded room, where she shot and killed twelve of them before being stopped by a fellow teacher, Mrs. Crossen.
Tomorrow a bad thing will happen, Robert said.
Miss Sidley was sent to a mental institution, where she continued to believe that the children were monsters. During a therapy session with a group of disabled children, she became agitated and asked to be taken away. That night, she committed suicide by cutting her throat with a piece of broken mirror glass. The psychiatrist who had been treating her, Buddy Jenkins, became increasingly obsessed with watching the children, unable to take his eyes off them.