Tales of Secret Egypt by Sax Rohmer

A mendicant of unwholesome aspect crouched in the shadow of the narrow gateway at the entrance to the Sûk es-Saîgh, or gold and silver bazaar, having his one serviceable eye fixed in a malevolent stare upon something or someone immediately behind me.

It is part and parcel of my difficult profession to subdue all impulses and to think before acting. I sipped my coffee and selected a fresh cigarette from the silver box upon the rug beside me. In this interval I had decided that the one-eyed mendicant cherished in his bosom an implacable and murderous hatred for my genial friend, Ali Mohammed, the dealer in antiques; that he was unaware of my having divined his bloody secret; and that if I would profit by my accidental discovery, I must continue to feign complete ignorance of it.