Folk legends suggest that dragons summon the rains by drawing water from rivers, a notion one should treat with skepticism. Xu Dong, on his solitary southern journey, moored his boat by the riverbank. There, he witnessed a verdant dragon descending from the clouds, its tail stirring the river water until waves surged and gathered toward the beast. He distinctly saw the water shimmer—the vast expanse was brighter than three lengths of white silk—before the dragon’s tail retracted, and the ripples subsided. Soon after, the rain fell in torrents, filling every channel and ditch.