This episode is a Chinese version of “Document 72 Hours” produced by a Chinese production company. The setting is Kunming, Yunnan Province. Blessed with a warm climate throughout the year, in autumn, flocks of black-tailed gulls arrive here from Siberia. There is a large pond in the park in the center of the city, where thousands of seagulls rest their wings for several months until spring. In the spring, when the seagulls fly away, what kind of feelings do people have as they see them off?