Then, too, there was the strangeness of the night talks their leader was known to have with his secret _Kambu_ fetish which was able to answer him in a squeaky but distinct voice in some unknown tongue, obviously a language of the djinn. The _Kambu_ was worn on a strap on Omar's wrist, and each night at a given hour he was wont to withdraw to his tent and there confer. On the fourth night, obviously, he was given instruction by the _Kambu_ for in the morning, at first light, the smiths hurriedly packed, broke camp, made their good-byes to Moussa-ag-Amastan and the others and were off. Moussa-ag-Amastan was glad to see them go. They were quite the most disturbing element to upset his people in many seasons. He wondered at the advisability of making their usual summer journey to the Tuareg sedentary centers. He had a feeling that if the clan got near enough to such centers as Zinder to the south, or Touggourt to the north, there would be wholesale desertion of the Bela, and, for that matter, even of some of his younger warriors and their wives. However, there was no putting off indefinitely exposure to this danger. Even in such former desert centers as Tessalit and In Salah, the irrigation projects were of such magnitude that there was a great labor shortage. But always, of course, as the smiths had said, if you worked at the projects your children must needs attend the schools. And that way lay disaster! The five smiths took out overland in the direction of Djanet on the border of what had once been known as Libya and famed for its cliffs which tower over twenty-five hundred feet above the town. Their solar powered, air cushion, hover-lorries, threw up their clouds of dust and sand to right and left, but they made good time over the _erg_. A good hovercraft driver could do much to even out a rolling landscape, changing his altitude from a few inches here to as much as twenty-five feet there, given, of course, enough power in his solar batteries, although that was little problem in this area where clouds were sometimes not seen for years on end. This was back of the beyond, the wasteland of earth. Only the interior of the Arabian peninsula and the Gobi could compete and, of course, even the Gobi was beginning to be tamed under the afforestation efforts of the teeming multitudes of China who had suffered its disastrous storms down through the millennia. * * * * * Omar checked and checked again with the instrument on his wrist, asking and answering, his voice worried. Finally they pulled up beside a larger than usual wadi and Omar ben Crawf stared thoughtfully out over it. The one they had named Abrahim el Bakr stood beside him and the others slightly to the rear. Abrahim el Bakr nodded, for once his face unsmiling. "Those cats'll come down here," he said. "Nothing else would make sense, not even to an Egyptian."