Lawrence would gladly have gone on at once, but Yussuf signed to him to be silent; and it was as well, for he had hardly time to throw himself down on a block of stone, and sham sleep, when the guards came sauntering in and looked suspiciously round. Then, not seeing two of their prisoners, they came on cautiously, and peered over the stones that hid them from where the professor was drawing, to find Yussuf apparently asleep, and Lawrence sharpening his pocket-knife upon a stone.

One of the men came forward and snatched the knife away, saying in his own tongue that boys had no business with knives, after which he stalked off and returned to his old place outside.

“You see,” said Yussuf quietly, “it was no time now for examining the place; wait till night.”

For the first time since he had been a prisoner the hours passed slowly to Lawrence. It seemed as if it would never be night, and every time he met the professor’s or Mr Burne’s eye, they seemed to be taking him to task for keeping a secret from them.

Then, too, Mrs Chumley appeared to be suspecting him, and Chumley drew him aside as if to cross-examine him; but it was only to confide a long story about how severely he had been snubbed that day for wanting to follow the professor to the ruins where he was making his drawings.

At last, though, the guards had thrust in their villainous faces for the last time, according to their custom, and all had lain down as if to sleep.

An hour must have passed, and Lawrence lay with his heart beating, waiting for a summons from Yussuf; but it seemed as if one would never come, and the lad was about to give up and conclude that their guide had decided not to go that night, when a hand came out of the darkness and touched his face, while a pair of lips almost swept his ear, and a voice whispered:

“Rise softly, and follow me.”

Lawrence needed no second invitation, and, rising quickly, he followed Yussuf to where the rug hung over the door.

“Bend down low, and follow me,” whispered the Turk. “The guards are nearly asleep.”