An aftershock caused by an earthquake twelve years ago caused a certain space-time connection between Xiao Li and his childhood. At a reunion many years later, Xiao Li reunited with Song Qian, a girl who had a crush on him. The secret of his father's disappearance and the memory of an accident caused by hide-and-seek were gradually recalled. In the flowing river, Xiao Li gradually gets closer to the truth in his heart and resists the forgetfulness from the present.