The desert was all sand in some stretches, and rocky in others. When the caravan was blocked by a boulder, it had to go around it; if there was a large rocky area, they had to make a major detour. If the  sand was too fine for the animals’ hooves, they sought a way where the sand was more substantial. In some places, the ground was covered with the salt of dried-up lakes. The animals balked at such places, and the camel drivers were forced to dismount and unburden their charges. The drivers carried the freight themselves over such treacherous footing, and then reloaded the camels. If a guide were to fall ill or die, the camel drivers would draw lots and appoint a new one.

But all this happened for one basic reason: no matter how many detours and adjustments it made, the caravan moved toward the same compass point. Once obstacles were overcome, it returned to its course, sighting on a star that indicated the location of the oasis. When the people saw that star shining in the morning sky, they knew they were on the right course toward water, palm trees, shelter, and other people.