Ma Yanwei, a master of ecology, and his wife Li Bei, a returnee, two sons, and a dog rented several hundred acres of land on the edge of the desert, hoping to improve the soil through ecological agriculture, slow down desertification, and protect the ecology. The arrival of the seagulls is like a mirror, but also like a sharp blade that pierces the bright moon that Yanwei raised for Li Bei over the long field in the sand sea.