在这部白夜行爱情/悬疑片中,太阳到达最高点的时候，它的影子便消失了。刑警韩东秀（韩石圭 饰）为了证实自己对一起已有定论的杀人案的猜想，致使自己的儿子意外身亡，从此变得意志消沉起来。14年后，一桩杀人案似乎和当年这起案件有着某种联系，当韩东秀再一次开始关注起当年一名被害人的儿子有汉（高修 饰）时，意外认识正在帮助财团老板调查未婚妻柳美皓（孙艺珍 饰）的私家侦探，从私家侦探那里得知这名叫柳皓美的女人正是当年被认为是畏罪自杀的凶手的女儿李佳。当年这两个韩东秀曾经有怀疑过的小孩子如今长大成人，而且又同样因为凶杀案出现在他的周围。在韩东秀的追查过程中，他发现了当年凶杀案以及近期凶杀案的真相，而真相背后，却是一对永远不能在光天化日之下见面的苦恋情侣。 　　影片改编自日本著名推理小说家东野圭吾的同名小说《白夜行》。小说曾在日本被拍成电视剧，并大获成功。

A pawnbroker is found murdered in a remote town. Police suspect that he was murdered by an acquaintance, as even the most experienced investigator on the case could identify no signs of resistance. Three people come under suspicion but all of them have perfect alibis and the investigation comes to a standstill. One year later, one of them is found dead and the original murder case becomes even more mysterious. Almost fifteen years pass and the lead inspector, now approaching retirement, reflects on the only case he could not solve in an otherwise successful career. Haunted by a sense of responsibility and guilt that he caused suffering by letting the murder case go unsolved, he decides to re-investigate. His persistent search brings attention to the long forgotten case and reveals a hidden relationship between the victim's son and the neighborhood woman's daughter. As their love grows, more crimes happen. As their sin grows, the inspector's chase comes closer to them.

【非影评】关于白夜行原作，和对日韩两版剧本的横向对比。__不是辩解。是理解。___关于李佳。。韩版《白夜行》不懂夜的黑。热门小说电影化。去其精华的泡菜版煽情白夜行。男主心路历程猜想。我尽了自己的全力，只是为了要给你在太阳下织毛衣的权力，不管是不是给傻逼。天鹅之死。《白夜行》：“坏”小说，“好”电影。爱无罪，罪无赦。