Mona Gray is a 20-year-old loner who, as a child, turned to math for salvation after her father became ill. As an adult, Mona now teaches the subject and must help her students through their own crises.
![An-Invisible-Sign-2010](http://193.22.146.146/wp-content/uploads/2018/06/An-Invisible-Sign-2010.jpg)
Mona Gray is a 20-year-old loner who, as a child, turned to math for salvation after her father became ill. As an adult, Mona now teaches the subject and must help her students through their own crises.