5.3 BlurayAn Invisible Sign (2010) 07 Oct 2010 An Invisible Sign IMDb: 5.3 2010 96 min min 92 views 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 ... ComedyDramaFamilyRomance