An Invisible Sign – After a stroke of her father, the weird Mona Gray gives up of all the things she likes expecting that her father will be better. When she is 20 year-old, she is expelled from home by her mother to live her own life. Soon her mother lies to her friend Ms. Gelband, who is principal of a school, telling that Mona Gray is graduated and she hires her to teach mathematic to the third grade. Mona Gray feels affection for the orphan Lisa Venus and her odd behavior attracts the attention of the teacher Ben Smith. When there is an incident at school, the life of Mona Gray changes for good.