All that is visible across the succession of deep, folding valleys hidden in darkness before me is the faintest outline of a sawtooth silhouette lancing up into a dazzling array of stars. I am standing alone on the rooftop of the dingy Pearl Hotel in Feilai Si, a small town that clings to a mountainside in southwestern China. Around me is a ghostly shroud of hotel linens that luff gently in the night breeze, seeming to mimic the Tibetan prayer flags fluttering on the hill behind. Otherwise, there is silence.