为所应为[电影解说]

世珍（高小英）独自住在一幢高层豪华公寓中的一间。某日深夜，拖着疲惫身躯在地铁站等车时，一神秘女子突然将她拉住欲一起跳轨，惊魂甫定，女子已命丧黄泉。加上工作中为如何布置橱窗以迎即将到来的圣诞节与合作伙伴发生冲突，她开始夜夜被噩梦折磨。勉强称作开心的事，是某日晨跑时结识住于对面公寓的残疾女孩柔妍（张熙珍）。柔妍自言父母虽然双亡，却托好心邻居照料活得幸福，并在谈话结束一刻，相交她一个魔方。
世珍察觉到柔妍所住的房间有异样，之后用望远镜夜夜观察，更发现时间每走到9点56分，整幢公寓便会齐齐熄灯，而次日清晨，会有一具尸体被拖出。世珍的行为被女高中生（朴夏善）发现并告知母亲，其母报警，但世珍没将警察的警告当回事。不久，女高中生主动向世珍道歉，两人成为朋友，而她屡屡玩不转魔方令世珍发现藏于其中的与柔妍有关的秘密，倒吸一口凉气。

这是一种名叫康普茶的饮料，它可以改变人的思维，使员工工作到死。

　　A little boy waits to meet his best friend to celebrate Halloween. When she at least appears, boy's mother makes a photo in her tablet and both walk house by house looking for trick-or-treat. Meanwhile he obtains several candies, she obtains no one, and he shares his candies with her, as well as both did the previous year. But when both come back to his home, he jokes with a man thinking that he's a fake doctor, taking a diagnosis paper from his hands, making that his mother runs behind her son. When accidentally the boy reads the diagnosis, he surprises with the words "Imaginary friend". Although the doctor and his parents says that she friend isn't true (showing him the photo of the tablet, where he's alone, instead with her at side of him), he claims her for real. After boy and girl run away returning to the hill, parents and police looking for the boy, making a macabre and unexpected discovery. Written by Chockys