The story begins with four young men making a pact under an old locust tree: they will stay with each other for the rest of their lives and never leave.
The course of the story is that the war is raging across the north, they join the army to fight, and meet all kinds of passers-by along the way - there is no absolute between good and evil. The young man's spirit was crushed by the flames of war, and the faces he passed side by side disappeared one by one.
The ending of the story is that after the fierce battle, no one saw them again. Only the old locust tree blooms every year, and its broken white petals fall all over the empty courtyard and return to dust.
