Travel is for parting, or perhaps, for reunion.Newlyweds Lin Xiushan (played by Zhang Zifeng) and Wang Rui (played by Hu Xianxu) work in different cities. They meet once a month traveling on a slow train. They set the alarm clock, make love, then part ways again at dawn. In an era without cellphones, this was the norm for long-distance relationships.On the day of the Mid-autumn Festival, the two young people unexpectedly get a day off. They each want to surprise the other, but fate has other plans. Throughout the day, they keep missing each other as they travel between the two cities, always a step too late.On the two trains going in opposite directions, they encounter a variety of individuals: some celebrating, some parting, and some facing life and death. After a long exhausting day, the young couple have both tasted the bittersweetness of life and love.Under the watchful moon, as they are about to give up, fate finally seems to answer their prayers...