The feathered serpent seemed oblivious to us. It flew on through the night, powerful wings beating a steady rhythm. The feathers that lay sleek against its long, serpentine body rustled gently in the wind. Occasionally its head turned as it scanned the ground below and, with a flick of its tail, changed direction. It seemed to be navigating by the dark ribbons of river canyon, which it followed for a time, and by the lights of the towns that we were passing. We crossed a wide expanse of river that I guessed must be the Rio Grande, and ahead in the distance I could see a larger smudge of yellow light framed by mountains, one of them shaped like a saddle.