imagination needed artificial stimulants.

Meticulous observation undeceived me. There was nothing suspicious in
this respect. Moreover, he rarely drank and almost never smoked.

And nevertheless, there was no means of denying the increase of his
disquieting feverishness. He returned from his expeditions each time
with his eyes more brilliant. He was paler, more animated, more
irritable.

One evening he left the post about six o'clock, at the end of the
greatest heat of the day. We waited for him all night. My anxiety was
all the stronger because quite recently caravans had brought tidings
of bands of robbers in the neighborhood of the post.

At dawn he had not returned. He did not come before midday. His camel
collapsed under him, rather than knelt.

He realized that he must excuse himself, but he waited till we were
alone at lunch.

"I am so sorry to have caused you any anxiety. But the dunes were so
beautiful under the moon! I let myself be carried farther and
farther...."

"I have no reproaches to make, dear fellow, you are free, and the
chief here. Only allow me to recall to you certain warnings concerning
the Chaamba brigands, and the misfortunes that might arise from a
Commandant of a post absenting himself too long."