In the birch forest of a small town at this time, Wang Xiang, a taxi driver, could never expect to meet the person that he most wants or fears to meet in his entire life. Is he an enemy or a friend? Since he has met him, he has to get closure, not just for him but also for his son. In the birch forest of a small town at that time, Wang Xiang, a train driver, was full of vigour and vitality, for he was driving a steel monster with twenty carriages. But on the one hand, he failed to run a small family of three filled with trivial matters. On the other hand, he was trapped in a faltering factory with a crisis looming up from every corner. A pack of unidentified body parts was dropped in the birch forest, just like a stone into the calm water. For the past twenty years, Wang Xiang could never stop thinking about that pack, not even when the leaves in the fall turned yellow. A lost father, a dead lover and old friends meeting up again were trapped in three different eras because of an unsolved mystery. All they want is to find a truth that travels through the past, the present and the future. When the mystery is revealed, only the elegy of fate and the era is left in the long season with time and space intertwined together.