There was always that low-sounding reverberation in these huge empty caverns beneath the surface, when the harsh wind blew and its icy claws dug into the earth wherever it might, and blustered and gusted and stormed its way downward into the earth as deep as it was able. All the while, the sound of these gales could be heard from miles off, giving an unsettling, constant ambiance even here, where the earth was still grey and cold from the frozen northlands above.