The ground sloped upward to the foot of Ngranek, thinly covered with scrub oaks and ash trees, and strewn with bits of rock, lava, and ancient cinder. There were the charred embers of many camps, where the lava-gatherers were wont to stop, and several rude altars which they had built either to propitiate the Great Ones or to ward off what they dreamed of in Ngranek's high passes and labyrinthine caves. At evening Carter reached the farthermost pile of embers and camped for the night, tethering his zebra to a sapling and wrapping himself well in his blankets before going to sleep. And all through the night a voonith howled distantly from the shore of some hidden pool, but Carter felt no fear of that amphibious terror, since he had been told with certainty that not one of them dares even approach the slope of Ngranek.