There was no conversation between the archæologist and the natives, for each seemed busy with his thoughts. Bob was extremely grave, and he wondered what was taking place in the adjoining room. Perhaps the Arabs wished to sell Fekmah something and did not wish to be thwarted by the whites. Or perhaps they wanted to engage themselves as guides on the coming expedition and knew they would have a better chance with Fekmah than with the Americans. But whatever it was, Bob felt uneasy. If their friend did not return before long he would go after him, the youth thought. "We'll wait a few more minutes," said Dr. Kirshner. "Then----" "Listen!" commanded Bob. "What was that?" "I didn't hear anything. What----" "There it is again. Sounds like a muffled cry for help. It's--it's Fekmah!" CHAPTER V A Fight for Freedom Bob was on his feet in an instant and dashed toward the door to the next room. But two of the Arabs were there first. With a catlike quickness they drew knives and advanced on the Americans. The other two natives came at them from the side. "What does this mean?" demanded Dr. Kirshner, looking from one to the other, his black eyes snapping with anger. "You are going to die!" was the grim answer from an evil-looking, flat-nosed fellow. He moved forward a step or two. Bob did not understand the man but sensed that something sinister was to take place. He noticed the look of anger and anxiety on the scientist's face. With a sudden movement he drew out his automatic, at the same time stepping back several feet. His action was so quick that the Arabs were taken by surprise and stood for several moments trying to grasp the true meaning of it all. "Now get back!" he commanded, flashing the shining pistol in their faces. "Take away their knives," he said to Dr. Kirshner. "I've got them covered. Tell them I'll shoot the first man who makes a forward move." The scientist did as directed and found that, beyond a vicious-looking knife, they were unarmed. "You stay here and guard them," said Bob. "I'm going in and see what's happened to Fekmah." He moved over to the door and opened it. Holding the pistol in readiness, he walked slowly in the room. One glance told him that no one was in sight. But there was a door leading into a large alcove, and it was possible that he could find someone there. Perhaps the Arabs were in hiding, having sensed that they were in danger. Tiptoeing as quietly as possible, Bob made his way to the closed door. He stood for several moments wondering what to do next. Then he decided to make a bold move. Clutching his tiny automatic tightly, he took hold of the knob and with a sudden twist threw open the door. The next instant he shrank back, for a tall Arab was almost upon him. The man held a vicious-looking knife in his uplifted right hand and was apparently ready to open the door when Bob did so first.