He was fidgeting in nervous impatience before the chanting and bowing were over, but presently they rose and passed into the tunnel which opened behind the idol. Their torches bobbed away into the nighted vault, and he followed swiftly. Not much danger of being discovered. He glided along the shadows like a creature of the night, and the black priests were completely engrossed in their ceremonial mummery. Apparently they had not even noticed the absence of Gwarunga. Emerging into a cavern of huge proportions, about…