Domini was roused from her contemplation of the mirage and the daydreams it suggested by the approach of this small cavalcade.  The officer was almost upon her ere she heard the clatter of his mule among the stones.  She looked up, startled, and he looked down, even more surprised, apparently, to see a lady ensconced at the foot of the tower.  His astonishment and exhaustion did not, however, get the better of his instinctive good breeding, and sitting straight up in the saddle he took off his sun helmet and asked Domini’s pardon for disturbing her.

“But this is my home for the night, Madame,” he added, at the same time drawing a key from the pocket of his loose trousers.  “And I’m thankful to reach it. Ma foi! there have been several moments in the last days when I never thought to see Mogar.”

Slowly he swung himself off his mule and stood up, catching on to the saddle with one hand.

“F-f-f-f!” he said, pursing his lips.  “I can hardly stand.  Excuse me, Madame.”

Domini had got up.

“You are tired out,” she said, looking at him and his men, who had now come up, with interest.

“Pretty well indeed.  We have been three days lost in the great dunes in a sand-storm, and hit the track here just as we were preparing for a—­well, a great event.”

“A great event?” said Domini.

“The last in a man’s life, Madame.”

He spoke simply, even with a light touch of humour that was almost cynical, but she felt beneath his words and manner a solemnity and a thankfulness that attracted and moved her.

“Those terrible dunes!” she said.

And, turning, she looked out over them.

There was no sunset, but the deepening of the grey into a dimness that seemed to have blackness behind it, the more ghastly hue of the white plains of saltpetre, and the fading of the mirage sea, whose islands now looked no longer red, but dull brown specks in a pale mist, hinted at the rapid falling of night.

“My husband is out in them,” she added.

“Your husband, Madame!”

He looked at her rather narrowly, shifted from one leg to the other as if trying his strength, then added: 

“Not far, though, I suppose.  For I see you have a camp here.”

“He has only gone after gazelle.”

As she said the last word she saw one of the soldiers, a mere boy, lick his lips and give a sort of tragic wink at his companions.  A sudden thought struck her.

“Don’t think me impertinent, Monsieur, but—­what about provisions in your tower?”

“Oh, as to that, Madame, we shall do well enough.  Here, open the door, Marelle!”

And he gave the key to a soldier, who wearily dismounted and thrust it into the door of the tower.

“But after three days in the dunes!  Your provisions must be exhausted unless you’ve been able to replenish them.”

“You are too good, Madame.  We shall manage a cous-cous.”