A biting chill, sharp as a dagger's edge, slips through the observatory's cracked casement, carrying the resinous breath of pines and the dank perfume of rain-soaked earth. The mercury barometer stands immobile at 29.96 inches, its silvery column a silent sentinel over the valley's descent into spectral gloom. Below, the river fog writhes like a living shroud, dense and luminous under the waning crescent moon, which hangs low in a sky of scattered stars—cloud cover merely nine and thirty parts in the hundred. The thermometer records 40 degrees Fahrenheit, the dew point a mere two degrees shy, …