The wind in the northwest Gobi desert blows on the face like a knife, and can squeeze all the water out of the seams of a person's bones. The border patrol's off-road vehicle rolled over the gravel beach, and the yellow sand rolled up to cover the sky. Captain Wang Tieniu held a cigarette that was almost burning to his mouth, squinted at the endless desolation in front of him, and cursed: "Damn it, you can't even see a bird in this damn place, and the superiors asked us to search all night, what the hell!"