"But, sir—" began Robert Cairn.
"You know the way," said the doctor, with an air of finality. "There is not a moment to waste, and although I fear that we are too late, it is just possible we may be in time to prevent a dreadful crime."
The tall Egyptian and Robert Cairn went stumbling off amongst the heaps of rubbish and broken masonry, until an angle of the great wall concealed them from view. Then the two who remained continued the climb yet higher, following the narrow, zigzag path leading up to the entrance of the descending passage. Immediately under the square black hole they stood and glanced at one another.
"We may as well leave our outer garments here," said Sime. "I note that you wear rubber-soled shoes, but I shall remove my boots, as otherwise I should be unable to obtain any foothold."
Dr. Cairn nodded, and without more ado proceeded to strip off his coat, an example which was followed by Sime. It was as he stooped and placed his hat upon the little bundle of clothes at his feet that Dr. Cairn detected something which caused him to stoop yet lower and to peer at that dark object on the ground with a strange intentness.
"What is it?" jerked Sime, glancing back at him.
Dr. Cairn, from a hip pocket, took out an electric lamp, and directed the white ray upon something lying on the splintered fragments of granite.
It was a bat, a fairly large one, and a clot of blood marked the place where its head had been. For the bat was decapitated!
As though anticipating what he should find there, Dr. Cairn flashed the ray of the lamp all about the ground in the vicinity of the entrance to the pyramid. Scores of dead bats, headless, lay there.
"For God's sake, what does this mean?" whispered Sime, glancing apprehensively into the black entrance beside him.