Reluctantly they made their way back and found that the scientists were ready to leave for the Arab friend's hotel. "We'll trust that we'll find him in his room, or in the lobby," said Mr. Holton, as he and the others followed Dr. Kirshner. "He'll probably be there," returned the archæologist. "He's expecting us over this morning to talk over the best procedure to find the hidden treasure." The hotel in which the Arab was staying was but a short distance up the street and around the corner. The explorers were barely within sight of the building when a figure rushed madly out of the door and came toward them. "Something the matter with that fellow?" asked Bob, surprised to see such haste from the native. "Looks that way," returned Mr. Holton. "He's----By George! It's our Arab friend. Wonder what has happened?" A moment later the man was up to them, his face white, his hands trembling. "The treasure map!" he cried in poor English. "It is gone!" CHAPTER III A Villainous Deed At the Arab's dread remark it seemed for a moment that the explorers were going to sink through the street. Dr. Kirshner reeled, and the perspiration came out on Mr. Holton's face. Mr. Lewis and the boys were spellbound. Gone! Hundreds of dollars--yes, thousands. After all this anticipating the good fortune of finding the supposedly hidden treasure. The explorers could hardly believe it. At last Dr. Kirshner got a grip on himself. "Do you have any idea where the thieves went?" he asked of the Arab, whose name was Fekmah. "No," was the reply. "They have complete disappeared. I try see where they go, but could not. They gone when I got to my room." "When did you first notice that the map had been taken?" inquired Bob in an anxious voice. "No more than ten minutes ago," Fekmah answered. "I had gone out to stay but a moment, and when came back to my room the door open and map gone. I run around to back and look out, but they gone." "Gone!" echoed Mr. Lewis. "We should have warned Fekmah to be on the lookout. If Bob and Joe had discovered the suspicious actions of the rascals sooner, it would have given us time to do so. But the fact that nothing strange was noticed till the night we were to reach port gave us no time to tell it." "So you knew?" asked the Arab friend. "You knew that robbers were after the map?" Dr. Kirshner nodded. "They broke into our rooms this morning, but when they couldn't find the map they left without taking anything else," he said. "We were just going over to warn you to be on the lookout and guard the map closely when we saw you." The Arab scowled and gritted his teeth. "Allah curse them!" he exclaimed, vexed all the more because of almost but not quite knowing in time. "It's too late now to find them, and they prob'ly gone by now." "Gone where?" asked Mr. Holton. Fekmah spread his hands apart in a wide gesture and then pointed to the south. "To get treasure," he said quietly.