The guards stood at the entrance leaning against the wall watching him and Lawrence carelessly, and then, going out into the sunshine, they picked out a sheltered spot, and sat down to smoke.
The professor began to draw. Soon afterwards Mr Burne sat down on a broken column taking snuff at intervals, and Yussuf seated himself with his back to the doorway, drew some worsted from his breast, and began to plait it rapidly, while Lawrence went on investigating the inmost recesses of the place.
“Come and look here, Yussuf,” he cried at the end of a few minutes, and the Turk followed him to a part of the building behind where an altar must have stood and pointed down.
“Look here,” he said; “this stone is loose, and goes down when I stand upon that corner. It’s hollow, too, underneath.”
He stamped as he spoke, and there was a strange echoing sound came up.
“Hush!” said Yussuf quickly, and he glanced round to see if they were observed; but they were hidden from the other occupants of the place; and, stooping down, Yussuf brushed away some rubbish, placed his hands under one side of the stone where it was loose, and lifted the slab partly up.
The air came up cool and sweet, so that it did not seem to be a vault; but it was evidently something of the kind, and not a well, for there was a flight of stone steps leading down into the darkness.
It was but a moment’s glance before Yussuf lowered the stone again, and hastily kicked some rubbish over it, and lowered a piece of an old figure across it so as to hide it more.
“What is it?” said Lawrence quickly.
“I do not know,” replied Yussuf. “It is our discovery. It may be treasure; it may be anything. Say no word to a soul, and you and I will get a lamp, escape from the prison to-night, and come and examine it, and see what it is. It may be a way out.”