宝猜带着花样年华的女儿西莲，回到位于台东都兰山上两层楼高的宅院，在阳光过盛的故乡，躲避着人群以及往昔男主人所凝聚而成的巨大阴影。 　　与世隔绝的宝猜，经历了离婚的变故，认定自己的破碎的心将永久的存封于这片山林间；在国小教书的西莲，却无法抑止向往蓝天外的爱情以及自由。 　　西莲与 表哥的爱情，在上一代的纠葛中被硬生生阻断，暗自伤心的西莲，在同事朱成的风趣体贴的言谈中，逐渐淡忘了初恋的哀伤，与朱成陷入热恋。 　　此时朱成突然接获学校命令被调派到绿岛，热恋中的情侣只有靠情书穿梭连结相互的思念。一封封的书信、一篇篇的文字，稳固了西莲对爱情的信念，坚定了要跨出这个幽闭世界的决心。 　　但是随后的情书却一再被宝猜拦截。在宝猜私密的阅读中，情书仿佛是写给自己一般，中年女人沉埋许久的情欲因此复苏流动。爱情，似乎在咫呎天涯。宝猜的秘密，却逐渐成为与西莲的隔阂与猜忌，两代的复杂纠结与冲突，显得如此之轻，又如此之重。

In a coastal village near Taidong during the 1960’s, a single, middle-aged mother, Bao-chai, lives a quiet life with her daughter, Xi-lian, a 20-year old schoolteacher. After conservative Bao-chai finds out that Xi Lian has fallen for her cousin, she forbids them to see each other. As time passes, Xi-lian finds love again, this time with Chu-cheng, a new teacher at her school from mainland China. When Chu-Cheng is relocated, he writes love letters to Xi-lian. Unknown to Xi-lian, the letters are intercepted and read by Bao-chai, who, in reading them, has feelings awakened in her that has been buried for most of her life. Then, one day, Chu-cheng comes to visit, and something happens that will change these three quiet lives forever…