Do we truly know one another? Every one of us has three lives: a public, a private and secret one. What we once stored in our memories is now being stored in our phones - what happens when these are made public?。廣秀遵循答應母親的遺願,將與好友承煥一同旅行,但在發現父親前往愛滋病診所的證據後,他為了跟蹤父親而違背承諾。在過程中,他看見母親的幻影,並發現父親曾與和尚相戀,於是他在深夜拋下病重的父親回去找承煥,兩人一同搭上一輛「明日列車」。。