The Truants by A.E.W. Mason

The village of Ain-Sefra stands upon a high and fertile oasis on the very borders of Morocco. The oasis is well watered, and the date-palm grows thickly there. It lies far to the south. The railway, in the days when Tony Stretton served in the Foreign Legion, did not reach to it; the barracks were newly built, the parade ground newly enclosed; and if one looked southwards from any open space, one saw a tawny belt of sand in the extreme distance streak across the horizon from east to west. That is the beginning of the great Sahara. Tony Stretton could never see that belt of sand, but his thoughts went back to the terrible homeward march from Bir-el-Ghiramo to Ouargla.

From east to west the Sahara stretched across Africa, breaking the soldiers who dared to violate its privacy, thrusting them back maimed and famine-stricken, jealously guarding its secrets and speaking by its very silence, its terrible "thus far and no farther," no less audibly, and a thousand times more truthfully than ever did the waves of the sea.