The colonel's ghostly smile. This smile contains many profound meanings and the bitterness of the head for many years. This is the first time that the animation director has shown his real voice. The slogan of dedicating one's heart to mankind is just to put on a coat for the real ideal. The colonel's life is to confirm his father's guess. He is desperate to find the truth so that one day he can expose the lies of the Wangs and comfort the people inside the wall, his father and himself. This smile contains all this. In the soldier's eyes, the ghostly smile contains a lot of sadness.