She held out her hand.

“Good-bye,” she added.

He took her hand, then signed to his men to ride on.  When they had passed, saluting her, he let her hand go.  He had not spoken a word.  His face, burned scarlet by the sun, had a look of exhaustion on it, but also another look—­of horror, she thought, as if in his soul he was recoiling from her.  His inflamed blue eyes watched her, as if in a search that was intense.  She stood beside the mule in amazement.  She could hardly believe that this was the man who had thanked her, with tears in his eyes, for her hospitality the night before.  “Good-bye,” he said, speaking at last, coldly.  She saw him glance at the tent from which she had come.  The horror in his face surely deepened.  “Goodbye, Madame,” he repeated.  “Thank you for your hospitality.”  He pulled up the rein to ride on.  The mule moved a step or two.  Then suddenly he checked it and turned in the saddle.  “Madame!” he said.  “Madame!”

She came up to him.  It seemed to her that he was going to say something of tremendous importance to her.  His lips, blistered by the sun, opened to speak.  But he only looked again towards the tent in which Androvsky was still sleeping, then at her.

A long moment passed.

Then De Trevignac, as if moved by an irresistable impulse, leaned from the saddle and made over Domini the sign of the cross.  His hand dropped down against the mule’s side, and without another word, or look, he rode away to the north, following his men.

CHAPTER XXI

That same day, to the surprise of Batouch, they left Mogar.  To both Domini and Androvsky it seemed a tragic place, a place where the desert showed them a countenance that was menacing.

They moved on towards the south, wandering aimlessly through the warm regions of the sun.  Then, as the spring drew into summer, and the heat became daily more intense, they turned again northwards, and on an evening in May pitched their camp on the outskirts of the Sahara city of Amara.

This city, although situated in the northern part of the desert, was called by the Arabs “The belly of the Sahara,” and also “The City of Scorpions.”  It lay in the midst of a vast region of soft and shifting sand that suggested a white sea, in which the oasis of date palms, at the edge of which the city stood, was a green island.  From the south, whence the wanderers came, the desert sloped gently upwards for a long distance, perhaps half a day’s march, and many kilometres before the city was reached, the minarets of its mosques were visible, pointing to the brilliant blue sky that arched the whiteness of the sands.  Round about the city, on every side, great sand-hills rose like ramparts erected by Nature to guard it from the assaults of enemies.  These hills were black with the tents of desert tribes, which, from far off, looked like multitudes of flies that had settled on the sands.  The palms of the oasis, which stretched northwards from the city, could not be seen from the south till the city was reached, and in late spring this region was a strange and barbarous pageant of blue and white and gold; crude in its intensity, fierce in its crudity, almost terrible in its blazing splendour that was like the Splendour about the portals of the sun.