That the robbers had been totally surprised was certain, for a loud chattering followed. Then the sand was thrown up, and they rode off at lightning speed.
Joe peeped around the corner of the dune.
“They aren’t going far,” he announced, following the Arabs’ movements closely. “They’ve stopped behind that sand hill over there.”
“By George!” exclaimed Mr. Holton. “They’re going to plant a battery, are they? Well, just let them waste their ammunition. We won’t fire until necessary.”
“We may need our bullets to use on those two thieves who stole Fekmah’s map,” said Bob to his chum, smiling.
The explorers waited ten minutes for the robbers to take the aggressive, but they did not.
“Well,” said Dr. Kirshner, turning about, “I’m going over and get our things packed back on the dromedaries. If nothing prevents, we want to get started in a short time now. It is much cooler, and we should cover a good distance by night.”
“We’ll stay here and guard a few minutes longer,” declared Mr. Lewis. “There’s no telling what those fellows may do.”
Suddenly a sound from the opposite direction caused them to turn about. Then their expressions changed.
Not fifty feet down the slope were the robbers, riding at full speed toward the explorers. The Arabs had their rifles in position to fire, which they were undoubtedly intending to do when slightly nearer.