18岁的男主角恩，被强征入伍，面对祖母的痴呆症、母亲偷恋军官，加上突如其来的祖父之死，挖出了亡父一段令人痛心疾首的过去；在追寻真相的同时，才意识到初恋的挽歌已经奏响，不堪回首的家族往事尽化轻烟。

　　巫俊锋，新加坡最多产的年轻电影人，学院派出身拍过无数得奖短片(《家庭写真》2009)，去年短片《丛林湾》入选柏林泰迪熊奖，处女长片《沙堡》重返他对爱家与国的情怀，成为狮城有史之来杀入康城影评人周之作。

一名新加坡少年对母亲所说的有关已故父亲的事情产生了怀疑，因为他从祖父那里得知自己的父亲曾是反政府学生的领袖。

En is an 18-year-old who has lost his father to cancer. As his family is drawn together in a sudden tragedy, he has to decide what he believes in. But in a country where ideologies are forged on constantly shifting sands, he struggles to stay true to what he knows to be right. And in a family that prefers to forget, the sandcastles of all he holds dear seem doomed to be washed away by the tides of time.

Sandcastle explores the relationship between the older and younger generation of Singaporeans through the lives of one particular family. Boo focuses on the lead character, En (Joshua Tan), who plays a typical 18-year old teenager, who while waiting to enlist for National Service discovers the secret past of his late father through his grandparents – his grandfather's old videos and photo negatives kept in a box, and the remnants of past memory from his Alzheimer-ravaged grandmother.