Hidden Letters tells the story of two Chinese women trying to balance their lives as independent women in modern China while confronting the traditional identity that defines but also oppresses them. Connected through their love for Nushu--a centuries- old secret text shared among women -- each of them transforms through a pivotal period of their lives and takes a step closer to becoming the individuals they know they can be.

一个上海姑娘顾晓霖来到鄱阳湖小岛，她说来拜访一位女知青，在这里教了一辈子书的刘老师。实际上她是来凭吊大学时的恋人潘岳，也就是刘老师的儿子，当年因为毕业时潘岳要回到这里，他们才分手的。 自从唯一的儿子死后，刘老师就一病不起，已经好久没来学校上课了。县里曾派过几个老师来这里，但都因条件太苦而先后离去。村长骗她留下来等刘老师，顺便代课，好应付县教委检查农村教育工作的事。她的留下使学校终于开课了。在代课的这段时间里，她隐隐地感悟到了潘岳为何放弃都市，放弃爱情的选择，感悟到了他母亲刘老师为何在这里三十多年教书的选择，也理解了孩子们渴望老师，渴望知识的愿望，最终，她选择了成为一名乡村女教师。